Liquid ejecting head chip, liquid ejecting head, and liquid ejecting apparatus

ABSTRACT

According to an embodiment, a liquid ejecting head chip includes an actuator plate and an in-channel electrode. In the actuator plate, a plurality of channels are arranged at a distance in an X-direction. Each of the channels includes an extension portion and a raise-and-cut portion. The extension portion extends in a Z-direction. The raise-and-cut portion continues from the extension portion toward one side of the Z-direction and has a groove depth which is gradually reduced toward the one side of the Z-direction. The in-channel electrode is formed on an inner surface of each of the channels, with a plating film.

RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119 to JapanesePatent Application No. 2017-018236 filed on Feb. 3, 2017, the entirecontent of which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a liquid ejecting head chip, a liquidejecting head, a liquid ejecting apparatus, and a manufacturing methodof the liquid ejecting head chip.

2. Description of Related Art

In the related art, as an apparatus that records an image or letters ona recording medium by discharging a droplet-like ink to the recordingmedium such as a recording sheet, an ink jet printer (liquid ejectingapparatus) including an ink jet head (liquid ejecting head) is provided.

For example, JP2011-131533A discloses a configuration in which aplurality of grooves which are arranged in a reference direction areprovided on one surface of a piezoelectric plate, one end portion ofeach of the grooves is opened to a side surface, and driving electrodesare provided on side walls of each of the grooves. In JP2011-131533A,each of the plurality of grooves which are formed on the one surface ofthe piezoelectric plate function as an actuator that discharges liquiddroplets. In JP2011-131533A, the grooves have the same shape as eachother, and the grooves respectively communicate with nozzles.

JP5047958B discloses a configuration in which an electrode is providedover at least a portion of a piezoelectric wall in a piezoelectricactuator in which an ink room having a shape of a long channel isformed. In JP5047958B, ink rooms have the same shape as each other, andthe ink rooms respectively communicate with nozzles.

As a method of forming an electrode, for example, a method usingelectroless plating is provided. However, according to the examinationof the inventors, a not-precipitated place may be provided in theplating film or a plating lump may be formed, in accordance with theshape of a groove in which an electrode is formed.

SUMMARY OF THE INVENTION

To solve the above problem, an object of the present invention is toprovide a liquid ejecting head chip, a liquid ejecting head, a liquidejecting apparatus, and a manufacturing method of the liquid ejectinghead chip, in which it is possible to suppress an occurrence of asituation in which a not-precipitated place is provided in a platingfilm or a plating lump is formed, in a plating electrode.

According to an aspect of the present invention, a liquid ejecting headchip includes an actuator plate and an in-channel electrode. In theactuator plate, a plurality of channels are arranged at a distance in asecond direction which is orthogonal to a first direction. Each of thechannels includes an extension portion and a raise-and-cut portion. Theextension portion extends in the first direction. The raise-and-cutportion continues from the extension portion toward one side of thefirst direction and has a groove depth which is gradually reduced towardthe one side of the first direction. The in-channel electrode is formedon an inner surface of each of the channels, with a plating film.

According to the examination of the inventors, a not-precipitated placemay be provided in the plating film or a plating lump may be formed, inaccordance with the shape of the channel (groove) in which an electrodeis formed. In particular, in a case where the plurality of channels isconfigured by a channel which has a cut-off shape and includes only anextension portion which extends in the first direction, and a channelwhich includes a raise-and-cut portion, it is clear that anot-precipitated place is easily provided in the plating film or aplating lump is easily formed. The reason is as follows. Regardingrinsing for removing a catalyst which becomes unnecessary after thecatalyst is imparted, the degree of the catalyst being removed variesdepending on the shape of a plating target. Thus, if a condition forimparting the catalyst is adjusted in accordance with one shape, in aplating target having another shape, the required amount of the catalystbecomes insufficient by excessive rinsing, and thus a not-precipitatedplace may be provided in a plating film. Otherwise, a plating lump maybe formed by insufficient rinsing. Therefore, in a case where anelectrode is formed by plating, it is considered that a condition forperforming plating on a target having a plurality of different shapes isdifficult. This state becomes more significant, if nozzle density isincreased and thus a groove width is reduced (for example, being equalto or smaller than 100 μm).

As a result of the close research, the inventors found the followingsand achieved the present invention. That is, the frequency of anot-precipitated place being provided in a plating film or a platinglump being formed has high correlation with the shape of a channel.Thus, if the shapes of a plurality of channels are set to be shapeshaving a common portion, it is possible to suppress an occurrence of asituation in which a not-precipitated place is provided in a platingfilm or a plating lump is formed.

According to this configuration, each of the plurality of channelsincludes the extension portion which extends in the first direction, andthe raise-and-cut portion which continues from the extension portiontoward one side of the first direction and has a groove depth which isgradually reduced toward the one side of the first direction. Thus, theshapes of the plurality of channels have a common portion. Thein-channel electrode is formed with a plating film, on the inner surfaceof each of the plurality of channels having shapes which have a commonportion. Thus, it is possible to suppress the occurrence of a situationin which a not-precipitated place is provided in a plating film or aplating lump is formed, in a plating electrode.

From a viewpoint of suppressing providing of a not-precipitated place ina plating film and forming of a plating lump, it is considered that eachof the plurality of channels is set to be a channel (simply referred toas “a channel having a cut-off shape” below) which has a cut-off shapein which a groove depth is uniform. However, in a case where each of theplurality of channels is set to be a channel having a cut-off shape,cracks or chipping may occur in an actuator plate, in a step of forminga plating electrode.

On the contrary, according to this configuration, each of the pluralityof channels includes a raise-and-cut portion. Thus, in comparison to acase where each of the plurality of channels is set to be a channelhaving a cut-off shape, this configuration is structurally robust.Accordingly, it is possible to suppress an occurrence of a situation inwhich cracks or chipping occurs in an actuator wafer, in the step offorming a plating electrode.

In the liquid ejecting head chip, the plurality of channels may haveshapes which are different from each other.

The shapes of a plurality of channels may be different from each other,in accordance with a type of ejecting a liquid from the plurality ofchannels. For example, the plurality of channels may be configured by achannel having a cut-off shape and a channel which includes araise-and-cut portion. However, in this case, it is clear that anot-precipitated place is easily provided in a plating film or a platinglump is easily formed.

On the contrary, according to this configuration, even in a case wherethe shapes of the plurality of channels are different from each other,it is possible to suppress the occurrence of a situation in which anot-precipitated place is provided in a plating film or a plating lumpis formed, in a plating electrode, because each of the plurality ofchannels includes the raise-and-cut portion. In addition, it is possibleto suppress the occurrence of a situation in which cracks or chippingoccurs in an actuator plate.

In the liquid ejecting head chip, the plurality of channels may includeejection channels and non-ejection channels which are alternatelyarranged at a distance in the second direction. The in-channel electrodemay include a common electrode formed on an inner surface of each of theejection channels and an individual electrode formed on an inner surfaceof each of the non-ejection channels. The length of the non-ejectionchannel in the first direction may be longer than the length of theejection channel in the first direction.

According to this configuration, in a type in which a liquid is ejectedfrom only ejection channels among a plurality of channels, it ispossible to suppress the occurrence of a situation in which anot-precipitated place is provided in a plating film or a plating lumpis formed, in a plating electrode. In addition, it is possible tosuppress the occurrence of a situation in which cracks or chippingoccurs in an actuator plate.

The liquid ejecting head chip may further include a cover plate and aconnection wiring. The cover plate is stacked on an actuator plate-sidefirst main surface of the actuator plate in a third direction which isorthogonal to the first direction and the second direction, so as toclose the ejection channels and the non-ejection channels in theactuator plate. In the cover plate, a liquid supply passage is formed tocommunicate with the ejection channel and a through-hole is formed topenetrate the cover plate in the third direction and disposed at a placein which the liquid supply passage is not formed. The connection wiringconnects the common electrode to an external wiring through thethrough-hole in the cover plate.

According to this configuration, the through-hole which penetrates thecover plate in the third direction and is disposed at a place in whichthe liquid supply passage is not formed is formed in the cover plate.The connection wiring connects the common electrode to an externalwiring through the through-hole. Thus, in comparison to a case where thecommon electrode is formed in a flow passage for an ink, it is possibleto reduce an occurrence of an electrode being provided in a place havinga probability of the electrode being corroded. Accordingly, it ispossible to suppress corrosion of an electrode due to a liquid such asan ink, and to improve reliability. In addition, in comparison to a casewhere the common electrode is formed in a flow passage for an ink, it ispossible to increase choices for electrode metal. In addition, it ispossible to secure an area of a region in which the connection wiringcan be formed, without being influenced by grooves such as the ejectionchannels and the non-ejection channels. In particular, in theconfiguration in which the ejection channels and the non-ejectionchannels are formed in the actuator plate, a region of forming thechannels can easily be complicated in comparison to a configuration inwhich only the ejection channels are formed. Thus, this is advantageousin that strength at a connection portion between various wirings issecured and the degree of freedom of layouts for the various wirings isimproved. In addition, since the connection wiring connects the commonelectrode to the external wiring, in the cover plate, it is possible tosuppress an increase of electrostatic capacity by separating theconnection wiring from the electrode on the actuator plate side, incomparison to a configuration in which the connection wiring is disposedon the actuator plate side.

In the liquid ejecting head chip, the connection wiring may be formed ata tail portion of the cover plate, which extends out of one end surfaceof the actuator plate in the first direction, in a stacked state of theactuator plate and the cover plate.

According to this configuration, it is possible to secure a wide area ofthe region in which the connection wiring can be formed, in the tailportion of the cover plate. Accordingly, it is easy to secure strengthat a connection portion between various wirings, and to improve thedegree of freedom of layouts for the various wirings.

In the liquid ejecting head chip, the connection wiring may include anin-through-hole electrode and a lead wiring. The in-through-holeelectrode is formed on an inner surface of the through-hole. The leadwiring connects the in-through-hole electrode to the external wiring atthe tail portion of the cover plate.

According to this configuration, it is possible to electrically connectthe common electrode to the external wiring at a position which avoidsthe liquid supply passage, through the in-through-hole electrode and thelead wiring. Therefore, it is possible to avoid an occurrence of asituation in which the connection wiring is brought into contact with aliquid such as an ink, which flows in the liquid supply passage.

In the liquid ejecting head chip, the lead wiring may include a commonterminal. In the tail portion of the cover plate, the common terminal isdivided so as to be formed in at least three or more places in thesecond direction on the cover plate-side first main surface facing theactuator plate-side first main surface. The common terminal is connectedto the external wiring.

According to this configuration, since the common terminal is formed onthe cover plate-side first main surface in the tail portion of the coverplate, it is possible to easily perform crimping work between theexternal wiring and the common terminal, in comparison to a case wherethe common terminal is formed on the cover plate-side second mainsurface. In addition, since the common terminal is divided so as to beformed in at least three or more places in the second direction, it ispossible to suppress an occurrence of dullness of a driving pulse, whichoccurs by a difference of a nozzle position in the second direction, incomparison to a case where the common terminal is partially formed (forexample, at both ends of the cover plate in the second direction).

In the liquid ejecting head chip, a plurality of actuator plate-sidecommon pads which respectively extend from the common electrodes and aredisposed to be spaced from each other in the second direction may beformed at a portion of the actuator plate-side first main surface, whichis positioned on one side of the ejection channel in the firstdirection. A plurality of cover plate-side common pads which extend fromin-through-hole electrodes, are disposed to be spaced from each other inthe second direction, and face the actuator plate-side common pads inthe third direction may be formed around through-holes in the coverplate-side first main surface of the cover plate, which faces theactuator plate-side first main surface, respectively.

According to this configuration, when the actuator plate and the coverplate are bonded to each other, the actuator plate-side common pad canbe connected to the cover plate-side common pad. Thus, it is possible toeasily connect the common electrode to the external wiring via the padsand the like. In addition, the common electrode formed on the innersurface of each of the plurality of ejection channels is conducted tothe in-through-hole electrode via the cover plate-side common pad fromthe actuator plate-side common pad, and the lead wiring connected to thein-through-hole electrode extends up to the tail portion of the coverplate. Thus, it is possible to easily perform electrode arrangement ofthe common electrode and the individual electrode.

In the liquid ejecting head chip, wherein a transverse common electrodewhich is connected to the plurality of cover plate-side common pads andextends in the second direction may be formed on the cover plate-sidefirst main surface.

According to this configuration, it is possible to collectively connectthe plurality of cover plate-side common pads to each other by thetransverse common electrode. Thus, in comparison to a case where theplurality of cover plate-side common pads are respectively connected toa plurality of electrodes on the actuator plate side, it is possible toimprove reliability of electric connection between the in-through-holeelectrodes and the plurality of cover plate-side common pads.

In the liquid ejecting head chip, on the actuator plate-side first mainsurface, an actuator plate-side individual wiring which extends in thesecond direction at one end portion thereof in the first direction andconnects individual electrodes which face each other with the ejectionchannel interposed between the individual electrodes to each other maybe formed. In the cover plate, on the cover plate-side first mainsurface which faces the actuator plate-side first main surface, a coverplate-side individual wiring which is divided in the second direction atthe one end portion thereof in the first direction may be formed. Thecover plate-side individual wiring may include a cover plate-sideindividual pad which faces the actuator plate-side individual wiring inthe third direction, and an individual terminal which extends from thecover plate-side individual pad toward one end in the first direction.

According to this configuration, when the actuator plate and the coverplate are bonded to each other, the actuator plate-side individualwiring can be connected to the cover plate-side individual pad. Thus, itis possible to easily connect the individual electrode to the externalwiring via the individual wiring, the individual pad, and the like.

According to another aspect of the present invention, a liquid ejectinghead includes the liquid ejecting head chip.

According to this configuration, in the liquid ejecting head whichincludes the liquid ejecting head chip, it is possible to suppress theoccurrence of a situation in which a not-precipitated place is providedin a plating film or a plating lump is formed, in a plating electrode.In addition, it is possible to suppress the occurrence of a situation inwhich cracks or chipping occurs in an actuator plate.

In the liquid ejecting head, the plurality of channels may includeejection channels and non-ejection channels which are alternatelyarranged at a distance in the second direction. The liquid ejecting headchip may include a cover plate which is stacked on an actuatorplate-side first main surface of the actuator plate in a third directionwhich is orthogonal to the first direction and the second direction, soas to close the ejection channels and the non-ejection channels in theactuator plate, and in which a liquid supply passage which communicateswith the ejection channel is formed. A pair of liquid ejecting headchips which are disposed such that cover plate-side second main surfaceswhich are opposite to cover plate-side first main surfaces respectivelyfacing the actuator plate-side first main surfaces in the cover platemay face each other in the third direction. A flow passage plate may bedisposed between the pair of liquid ejecting head chips, and an inletflow passage which communicates with liquid supply passages of the pairof the cover plates may be formed in the flow passage plate.

According to this configuration, in each of the liquid ejecting headchips, the cover plate-side first main surface is exposed to the outsidethereof in the third direction. Thus, it is possible to easily connectthe external wiring to the connection wiring in a two-row type liquidejecting head.

In the liquid ejecting head, each of the plurality of ejection channelsmay be opened in the other end surface of the actuator plate in thefirst direction in each of the pair of liquid ejecting head chips. Anejection plate which has ejection holes which respectively communicatewith the ejection channels may be disposed on the other end side of eachof the pair of actuator plates in the first direction. A return platewhich has circulation passages which cause the ejection channels torespectively communicate with the ejection holes may be disposed betweenthe pair of actuator plates and the ejection plate in the firstdirection. An outlet flow passage which communicates with thecirculation passages may be formed in the flow passage plate.

According to this configuration, it is possible to circulate a liquidbetween each of the ejection channels and a liquid tank. Thus, it ispossible to suppress staying of bubbles in the vicinity of the ejectionhole in the ejection channel.

According to still another aspect of the present invention, a liquidejecting apparatus includes the liquid ejecting head and a movingmechanism. The moving mechanism relatively moves the liquid ejectinghead and a recording medium.

According to this configuration, in the liquid ejecting apparatus whichincludes the liquid ejecting head, it is possible to suppress theoccurrence of a situation in which a not-precipitated place is providedin a plating film or a plating lump is formed, in a plating electrode.In addition, it is possible to suppress the occurrence of a situation inwhich cracks or chipping occurs in an actuator plate.

According to still another aspect of the present invention, amanufacturing method of a liquid ejecting head chip includes a channelforming step and an electrode forming step. In the channel forming step,a plurality of channels are formed in an actuator wafer so as to bearranged at a distance in a second direction which is orthogonal to afirst direction. Each of the plurality of channels includes an extensionportion which extends in the first direction and a raise-and-cut portionwhich continues from the extension portion toward one side of the firstdirection and has a groove depth which is gradually reduced toward theone side of the first direction. In the electrode forming step, aplating film is formed as an in-channel electrode, on an inner surfaceof each of the channels after the channel forming step.

According to this method, in the channel forming step, the plurality ofchannels of which each includes the extension portion which extends inthe first direction, and the raise-and-cut portion which continues fromthe extension portion toward one side of the first direction and has agroove depth which is gradually reduced toward the one side of the firstdirection are formed. Thus, the shapes of the plurality of channels havea common portion. In the electrode forming step, the plating film isformed as the in-channel electrode, on the inner surface of each of theplurality of channels having shapes which have a common portion. Thus,it is possible to suppress the occurrence of a situation in which anot-precipitated place is provided in a plating film or a plating lumpis formed, in a plating electrode. In addition, since each of theplurality of channels includes the raise-and-cut portion. Thus, incomparison to a case where each of the plurality of channels is set tobe a channel having a cut-off shape, this configuration is structurallyrobust. Accordingly, it is possible to suppress an occurrence of asituation in which cracks or chipping occurs in an actuator wafer, inthe electrode forming step.

According to the present invention, it is possible to provide a liquidejecting head chip, a liquid ejecting head, a liquid ejecting apparatus,and a manufacturing method of the liquid ejecting head chip, in which itis possible to suppress the occurrence of a situation in which anot-precipitated place is provided in a plating film or a plating lumpis formed, in a plating electrode.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic configuration diagram illustrating an ink jetprinter according to an embodiment.

FIG. 2 is a schematic configuration diagram illustrating an ink jet headand ink circulation means in the embodiment.

FIG. 3 is an exploded perspective view illustrating the ink jet head inthe embodiment.

FIG. 4 is a sectional view illustrating the ink jet head in theembodiment.

FIG. 5 is a sectional view illustrating the ink jet head in theembodiment.

FIG. 6 is a view illustrating a section taken along VI-VI in FIG. 5.

FIG. 7 is an exploded perspective view illustrating a head chip in theembodiment.

FIG. 8 is a perspective view illustrating a cover plate in theembodiment.

FIG. 9 is a process chart illustrating a wafer preparation step.

FIG. 10 is a process chart illustrating a mask pattern forming step inthe embodiment.

FIG. 11 is a process chart illustrating a channel forming step in theembodiment.

FIG. 12 is a process chart illustrating the channel forming step in theembodiment.

FIG. 13 is a process chart illustrating a catalyst impartation step inthe embodiment.

FIG. 14 is a process chart illustrating a mask removal step in theembodiment.

FIG. 15 is a process chart illustrating a plating step in theembodiment.

FIG. 16 is a process chart illustrating a plating film removal step inthe embodiment.

FIG. 17 is a process chart (plan view) illustrating a cover plateproduction step in the embodiment.

FIG. 18 is a view illustrating a section taken along XVIII-XVIII in FIG.17.

FIG. 19 is a diagram illustrating a common wiring forming step and anindividual wiring forming step in the embodiment.

FIG. 20 is a view illustrating a section taken along XX-XX in FIG. 19.

FIG. 21 is a diagram illustrating a flow-passage plate production stepin the embodiment.

FIG. 22 is a view illustrating a section taken along XXII-XXII in FIG.4, and is a process chart illustrating a various-plate bonding step.

FIG. 23 is an exploded perspective view illustrating a head chipaccording to a first modification example of the embodiment.

FIG. 24 is a sectional view illustrating an ink jet head according to asecond modification example of the embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment according to the present invention will bedescribed with reference to the drawings. In the embodiment, as anexample of a liquid ejecting apparatus which includes a liquid ejectinghead including a liquid ejecting head chip (simply referred to as “ahead chip” below) according to the present invention, an ink jet printer(simply referred to as “a printer” below) that performs recording on arecording medium by using an ink (liquid) will be described. In thedrawings used in the following descriptions, members are assumed to havea size which allows recognition of each of the members. Thus, the scaleof each of the members is appropriately changed.

Printer

FIG. 1 is a schematic configuration diagram illustrating a printer 1.

As illustrated in FIG. 1, the printer 1 in the embodiment includes apair of transporting means 2 and 3, an ink tank 4, an ink jet head(liquid ejecting head) 5, ink circulation means 6, and scanning means 7.In the following descriptions, descriptions will be made, if necessary,by using an orthogonal coordinates system of X, Y, and Z. An X-directionis a transport direction of a recording medium P (for example, paper). AY-direction is a scanning direction of the scanning means 7. AZ-direction is a vertical direction which is orthogonal to theX-direction and the Y-direction.

The transporting means 2 and 3 transport the recording medium P in theX-direction. Specifically, the transporting means 2 includes a gritroller 11, a pinch roller 12, and a driving mechanism (not illustrated)such as a motor. The grit roller 11 is provided to extend in theY-direction. The pinch roller 12 is provided to extend in parallel tothe grit roller 11. The driving mechanism rotates the shaft of the gritroller 11 so as to rotate the grit roller 11. The transporting means 3includes a grit roller 13, a pinch roller 14, and a driving mechanism(not illustrated). The grit roller 13 is provided to extend in theY-direction. The pinch roller 14 is provided to extend in parallel tothe grit roller 13. The driving mechanism (not illustrated) rotates theshaft of the grit roller 13 so as to rotate the grit roller 13.

A plurality of ink tanks 4 are provided to be arranged in one direction.In the embodiment, the plurality of ink tanks 4 respectively correspondto ink tanks 4Y, 4M, 4C, and 4K that accommodate inks of four colorswhich are yellow, magenta, cyan, and black. In the embodiment, the inktanks 4Y, 4M, 4C, and 4K are disposed side by side in the X-direction.

As illustrated in FIG. 2, the ink circulation means 6 is configured tocirculate an ink between the ink tank 4 and the ink jet head 5.Specifically, the ink circulation means 6 includes a circulation flowpassage 23, a pressure pump 24, and a suction pump 25. The circulationflow passage 23 includes an ink supply tube 21 and an ink discharge tube22. The pressure pump 24 is connected to the ink supply tube 21. Thesuction pump 25 is connected to the ink discharge tube 22. For example,the ink supply tube 21 and the ink discharge tube 22 are configured by aflexible hose which has flexibility and can follow an operation of thescanning means 7 for supporting the ink jet head 5.

The pressure pump 24 applies pressure to the inside of the ink supplytube 21, and thus an ink is sent to the ink jet head 5 through the inksupply tube 21. Thus, the ink supply tube 21 side has positive pressurein comparison to the ink jet head 5.

The suction pump 25 depressurizes the ink discharge tube 22, and thussuctions an ink from the ink jet head 5 through the ink discharge tube22. Thus, the ink discharge tube 22 side has negative pressure incomparison to the ink jet head 5. The ink may be circulated between theink jet head 5 and the ink tank 4 through the circulation flow passage23, by driving of the pressure pump 24 and the suction pump 25.

As illustrated in FIG. 1, the scanning means 7 causes the ink jet head 5to perform scanning with reciprocating, in the Y-direction.Specifically, the scanning means 7 includes a pair of guide rails 31 and32, a carriage 33, and a driving mechanism 34. The guide rails 31 and 32are provided to extend in the Y-direction. The carriage 33 is supportedso as to be able to move on the pair of the guide rails 31 and 32. Thedriving mechanism 34 moves the carriage 33 in the Y-direction. Thetransporting means 2 and 3, and the scanning means 7 function as amoving mechanism that relatively moves the ink jet head 5 and therecording medium P.

The driving mechanism 34 is disposed between the guide rails 31 and 32in the X-direction. The driving mechanism 34 includes a pair of pulleys35 and 36, an endless belt 37, and a driving motor 38. The pair ofpulleys 35 and 36 is arranged at a distance in the Y-direction. Theendless belt 37 is wound around the pair of pulleys 35 and 36. Thedriving motor 38 rotates and drives one pulley 35.

The carriage 33 is linked to the endless belt 37. A plurality of ink jetheads 5 are mounted in the carriage 33. In the embodiment, the pluralityof ink jet heads 5 respectively correspond to ink jet heads 5Y, 5M, 5C,and 5K that discharge inks of four colors which are yellow, magenta,cyan, and black. In the embodiment, the ink jet heads 5Y, 5M, 5C, and 5Kare disposed side by side in the Y-direction.

Ink Jet Head

As illustrated in FIG. 3, the ink jet head 5 includes a pair of headchips 40A and 40B, a flow passage plate 41, an inlet manifold 42, anoutlet manifold (not illustrated), a return plate 43, and a nozzle plate(ejection plate) 44. As the ink jet head 5, a circulation type (edgeshoot circulation type) of circulating an ink between the ink jet head 5and the ink tank 4, in a so-called edge shoot type of discharging an inkfrom the tip end portion of the discharge channel 54 in a channelextension direction is provided.

Head Chip

A pair of head chips 40A and 40B is a first head chip 40A and a secondhead chip 40B. Descriptions will be made below focusing on the firsthead chip 40A. In the second head chip 40B, component which are the sameas those of the first head chip 40A are denoted by the same referencesigns, and detailed descriptions thereof will not be repeated.

The first head chip 40A includes an actuator plate 51 and a cover plate52.

Actuator Plate

The appearance of the actuator plate 51 is a rectangular plate shapewhich is long in the X-direction and is short in the Z-direction. In theembodiment, the actuator plate 51 is a so-called Chevron type stackedsubstrate in which two piezoelectric substrates having polarizationdirections which are different from each other in a thickness direction(Y-direction) are stacked (see FIG. 6). For example, a ceramicssubstrate formed of PZT (lead titanate zirconate) or the like issuitably used as the piezoelectric substrate.

A plurality of channels 54 and 55 are formed in a first main surface(actuator plate-side first main surface) of the actuator plate 51 in theY-direction. In the embodiment, the actuator plate-side first mainsurface refers to an inner side surface 51 f 1 of the actuator plate 51in the Y-direction (referred to as “an AP-side-Y-direction inner sidesurface 51 f 1” below). Here, the inner side in the Y-direction meansthe center side of the ink jet head 5 in the Y-direction (the flowpassage plate 41 side in the Y-direction). In the embodiment, anactuator plate-side second main surface is an outer side surface of theactuator plate 51 in the Y-direction (indicated by the reference sign of51 f 2 in the drawings).

Each of the channels 54 and 55 is formed to have a straight-line shapewhich extends in the Z-direction (first direction). The channels 54 and55 are alternately formed to be spaced from each other in theX-direction (second direction). The channels 54 and 55 are defined fromeach other by a drive wall 56 formed by the actuator plate 51. Onechannel 54 is a discharge channel (ejection channel) 54 with which anink is filled. The other channel 55 is a non-discharge channel(non-ejection channel) 55 with which an ink is not filled.

An upper end portion of the discharge channel 54 is terminated in theactuator plate 51. A lower end portion of the discharge channel 54 isopened in a lower end surface of the actuator plate 51.

FIG. 4 is a diagram illustrating a section of the discharge channel 54in the first head chip 40A.

As illustrated in FIG. 4, the discharge channel 54 includes an extensionportion 54 a positioned at the lower end portion of the dischargechannel 54, and a raise-and-cut portion 54 b which continues upward fromthe extension portion 54 a.

The extension portion 54 a has a groove depth which is constant over theentirety thereof in the Z-direction. The raise-and-cut portion 54 b hasa groove depth which gradually becomes shallow while being raisedupwardly.

As illustrated in FIG. 3, an upper end portion of the non-dischargechannel 55 is opened in the upper end surface of the actuator plate 51.A lower end portion of the non-discharge channel 55 is opened in thelower end surface of the actuator plate 51.

FIG. 5 is a diagram illustrating a section of the non-discharge channel55 in the first head chip 40A.

As illustrated in FIG. 5, the non-discharge channel 55 includes anextension portion 55 a positioned at a lower end portion of thenon-discharge channel 55, and a raise-and-cut portion 55 b whichcontinues upward from the extension portion 55 a.

The extension portion 55 a has a groove depth which is constant over theentirety thereof in the Z-direction. The length of the extension portion55 a in the non-discharge channel 55 in the Z-direction is longer thanthe length of the extension portion 54 a (see FIG. 4) in the dischargechannel 54 in the Z-direction. The raise-and-cut portion 55 b has agroove depth which gradually becomes shallow while being raisedupwardly. The slope of the raise-and-cut portion 55 b in thenon-discharge channel 55 is substantially the same as the slope of theraise-and-cut portion 54 b (see FIG. 4) in the discharge channel 54.That is, in the discharge channel 54 and the non-discharge channel 55, aslope start position is different by a difference of the length in theZ-direction between the extension portions 54 a and 55 a, but the slopeitself (gradient, curvature) is substantially the same as each other.

The plurality of channels 54 and 55 have shapes which are different fromeach other. Specifically, the length of the non-discharge channel 55 inthe Z-direction is longer than the length of the discharge channel 54 inthe Z-direction. Here, the groove width of each of the channels 54 and55 is set to be W and the groove depth thereof is set to be D. Thegroove width W means the length of each of the channels 54 and 55 in theX-direction. The groove depth D means the length of each of the channels54 and 55 in the Y-direction. For example, regarding the extensionportion 54 a of the channel 54 and the extension portion 55 a of thechannel 55, the ratio D/W between the groove width W and the groovedepth D is set to be equal to or greater than 3 (D/W≥3).

As illustrated in FIG. 4, a common electrode 61 is formed on an innersurface of the discharge channel 54. The common electrode 61 is formedon the entirety of the inner surface of the discharge channel 54. Thatis, the common electrode 61 is formed on the entirety of the innersurface of the extension portion 54 a and on the entirety of the innersurface of the raise-and-cut portion 54 b.

An actuator plate-side common pad 62 (referred to as “an AP-side commonpad 62” below) is formed on an inner side surface of a portion 51 e(referred to as “an AP-side tail portion 51 e” below) of the actuatorplate 51, which is positioned over the discharge channel 54, in theY-direction. The AP-side common pad 62 is formed to extend from an upperend of the common electrode 61 to an inner side surface of the AP-sidetail portion 51 e in the Y-direction. That is, the lower end portion ofthe AP-side common pad 62 is connected to the common electrode 61 in thedischarge channel 54. The upper end portion of the AP-side common pad 62is terminated on the inner side surface of the AP-side tail portion 51 ein the Y-direction. The AP-side common pad 62 continues to the commonelectrode 61. As illustrated in FIG. 3, a plurality of AP-side commonpads 62 are disposed to be spaced from each other in the X-direction, onthe inner side surface of the AP-side tail portion 51 e (see FIG. 7) inthe Y-direction.

As illustrated in FIG. 5, an individual electrode 63 is formed on aninner surface of the non-discharge channel 55. As illustrated in FIG. 6,individual electrodes 63 are respectively formed on inner side surfaceswhich face each other in the X-direction, in the inner surface of thenon-discharge channel 55. Thus, among individual electrodes 63,individual electrodes 63 which face each other in the same non-dischargechannel 55 are electrically isolated on the bottom surface of thenon-discharge channel 55. The individual electrode 63 is formed over theentirety (entirety in the Y-direction and the Z-direction) of the innerside surface of the non-discharge channel 55.

As illustrated in FIG. 5, an actuator plate-side individual wiring 64(referred to as “an AP-side individual wiring 64” below) is formed onthe inner side surface of the AP-side tail portion 51 e in theY-direction. As illustrated in FIG. 3, regarding the AP-side individualwiring 64, a portion of on the inner side surface of the AP-side tailportion 51 e (see FIG. 7) in the Y-direction, which is positioned overthe AP-side common pad 62 extends in the X-direction. The AP-sideindividual wiring 64 connects individual electrodes 63 which face eachother with the discharge channel 54 interposed between the individualelectrodes 63.

Cover Plate

As illustrated in FIG. 3, the appearance of the cover plate 52 is arectangular plate shape which is long in the X-direction and is short inthe Z-direction. The length of the cover plate 52 in a longer sidedirection is substantially equal to the length of the actuator plate 51in the longer side direction. The length of the cover plate 52 in ashorter side direction is longer than the length of the actuator plate51 in the shorter side direction. A first main surface (cover plate-sidefirst main surface) of the cover plate 52, which faces theAP-side-Y-direction inner side surface 51 f 1 is bonded to theAP-side-Y-direction inner side surface 51 f 1. In the embodiment, thecover plate-side first main surface refers to an outer side surface 52 f1 of the cover plate 52 in the Y-direction (referred to as “aCP-side-Y-direction outer side surface 52 f 1” below). Here, the outerside in the Y-direction means an opposite side of the center side of theink jet head 5 in the Y-direction (opposite side of the flow passageplate 41 side in the Y-direction). In the embodiment, a cover plate-sidesecond main surface refers to an inner side surface 52 f 2 of the coverplate 52 in the Y-direction (referred to as “a CP-side-Y-direction innerside surface 52 f 2” below).

A liquid supply passage 70 is formed in the cover plate 52. The liquidsupply passage 70 penetrates the cover plate 52 in the Y-direction(third direction) and communicates with the discharge channel 54. Theliquid supply passage 70 includes a common ink room 71 and a pluralityof slits 72. The common ink room 71 is formed in a manner that the innerside of the cover plate 52 is opened in the Y-direction. The pluralityof slits 72 communicate with the common ink room 71. The slits 72 areopened in the outer side of the cover plate 52 in the Y-direction andare disposed to be spaced from each other in the X-direction. The commonink room 71 individually communicates with the discharge channels 54through the slit 72, respectively. The common ink room 71 does notcommunicate with the non-discharge channel 55.

As illustrated in FIG. 4, the common ink room 71 is formed in theCP-side-Y-direction inner side surface 52 f 2. The common ink room 71 isdisposed at a position which is substantially the same as that of theraise-and-cut portion 54 b of the discharge channel 54, in theZ-direction. The common ink room 71 is formed to have a groove shapewhich is recessed toward the CP-side-Y-direction outer side surface 52 f1 side and extends in the X-direction. An ink flows into the common inkroom 71 through the flow passage plate 41.

The slits 72 are formed in the CP-side-Y-direction outer side surface 52f 1. The slits 72 are disposed at positions which face the common inkroom 71 in the Y-direction. The slit 72 communicates with the common inkroom 71 and the discharge channel 54. The width of the slit 72 in theX-direction is substantially equal to the width of the discharge channel54 in the X-direction.

A through-hole 85 is formed in the cover plate 52. The through-hole 85penetrates the cover plate 52 in the Y-direction and is disposed at aplace in which the flow passages for an ink (liquid) is not formed. Thethrough-hole 85 is disposed at a position which avoids the liquid supplypassage 70 in the cover plate 52. The through-hole 85 is disposed at aportion of the cover plate 52, which is positioned on an upper part ofthe liquid supply passage 70. As illustrated in FIG. 3, a plurality ofthrough-holes 85 are disposed to be spaced from each other in theX-direction. The distance (array pitch) between two through-holes 85which are adjacent to each other is substantially equal. The array pitchbetween the through-holes 85 and the array pitch between the slits 72are substantially equal to each other. The through-hole 85 and the slit72 are disposed at substantially the same position in the X-direction.That is, the through-hole 85 and the slit 72 are disposed to be lined upin the Z-direction.

In the cover plate 52, an in-through-hole electrode 86 is formed on theinner surface of the through-hole 85. For example, the in-through-holeelectrode 86 is formed only on an inner circumferential surface of thethrough-hole 85 by vapor deposition or the like. The through-hole 85 maybe full of the in-through-hole electrode 86 by using a conductive pasteor the like.

As illustrated in FIG. 7, a common pad 66 on the cover plate side(referred to as “a CP-side common pad 66” below) is formed around thethrough-hole 85 in the CP-side-Y-direction outer side surface 52 f 1. Asillustrated in FIG. 4, the CP-side common pad 66 is formed to extenddownward from the in-through-hole electrode 86 toward theCP-side-Y-direction outer side surface 52 f 1. That is, the upper endportion of the CP-side common pad 66 is connected to the in-through-holeelectrode 86 in the through-hole 85. The lower end portion of theCP-side common pad 66 is terminated between the through-hole 85 and theslit 72 in the Z-direction, on the CP-side-Y-direction outer sidesurface 52 f 1. The CP-side common pad 66 continues to thein-through-hole electrode 86. The CP-side common pad 66 is separatedupwardly from the upper end of the slit 72. A plurality of CP-sidecommon pads 66 are disposed to be spaced from each other on theCP-side-Y-direction outer side surface 52 f 1 in the X-direction (seeFIG. 7).

The CP-side common pad 66 faces the AP-side common pad 62 in theY-direction. As illustrated in FIG. 7, the CP-side common pad 66 isdisposed at a position corresponding to the AP-side common pad 62 whenthe actuator plate 51 and the cover plate 52 are bonded to each other.That is, when the actuator plate 51 and the cover plate 52 are bonded toeach other, the CP-side common pad 66 and the AP-side common pad 62 areelectrically connected to each other.

As illustrated in FIG. 4, a common lead wiring (lead wiring) 67 isformed around the through-hole 85 in the CP-side-Y-direction inner sidesurface 52 f 2. As illustrated in FIG. 3, a plurality of recess portions73 are formed at the upper end of the cover plate 52. The recessportions 73 are recessed to the inner side of the cover plate 52 in theZ-direction, and are disposed to be spaced from each other in theX-direction. FIG. 3 illustrates four recess portions 73 which arearranged at a substantially equal interval in the X-direction.

As illustrated in FIG. 4, the common lead wiring 67 extends upwardly onthe CP-side-Y-direction inner side surface 52 f 2 from the through-hole85 along the CP-side-Y-direction inner side surface 52 f 2. Then, thecommon lead wiring 67 is drawn up to the upper end portion of theCP-side-Y-direction outer side surface 52 f 1 along the recess portion73 at the upper end of the cover plate 52. In other words, the commonlead wiring 67 is drawn up to the outer side surface of a portion 52 e(referred to as “a CP-side tail portion 52 e” below) of the cover plate52, which is positioned over the actuator plate 51, in the Y-direction.Thus, the common electrode 61 formed on the inner surface of each of theplurality of discharge channels 54 is electrically connected to aflexible substrate (external wiring) 45 in the common terminal 68,through the AP-side common pad 62, the CP-side common pad 66, thein-through-hole electrode 86, and the common lead wiring 67. In theembodiment, the common lead wiring 67 and the in-through-hole electrode86 constitute a connection wiring 60 which connects the common electrode61 and the flexible substrate 45 to each other. In the connection wiring60, the common lead wiring 67 is formed to be divided into at leastthree or more places in the cover plate 52 in the X-direction.

A joint common electrode 82 which is connected to a plurality of commonlead wirings 67 is formed on the CP-side-Y-direction inner side surface52 f 2. As illustrated in FIG. 3, the joint common electrode 82 isformed in a manner that a portion of the CP-side-Y-direction inner sidesurface 52 f 2 between two common lead wiring 67 which are adjacent toeach other extends in the X-direction. The joint common electrode 82 isformed to have a band shape in an arrangement direction (X-direction) ofa plurality of through-holes 85, on the CP-side-Y-direction inner sidesurface 52 f 2. The joint common electrode 82 is connected to lower endportions of the plurality of common lead wirings 67, on theCP-side-Y-direction inner side surface 52 f 2. The joint commonelectrode 82 is separated upwardly from the upper end of the common inkroom 71, on the CP-side-Y-direction inner side surface 52 f 2.

As illustrated in FIG. 7, the common lead wiring 67 includes commonterminals 68 which are divided so as to be formed in at least three ormore places in the X-direction, on the outer side surface of the CP-sidetail portion 52 e in the Y-direction. In the embodiment, 4 commonterminals 68 are arranged to be spaced from each other in theX-direction, on the outer side surface of the CP-side tail portion 52 ein the Y-direction. The distance between two common terminals 68 whichare adjacent to each other is substantially equal.

A cover plate-side individual wiring 69 (referred to as “a CP-sideindividual wiring 69” below) is formed in the cover plate 52. TheCP-side individual wiring 69 is formed to be divided in the X-direction,at the upper end portion of the CP-side-Y-direction outer side surface52 f 1. The CP-side individual wiring 69 includes a cover plate-sideindividual pad 69 a (referred to as “a CP-side individual pad 69 a”below) and an individual terminal 69 b. The CP-side individual pad 69 ais disposed at a position corresponding to the AP-side individual wiring64 when the actuator plate 51 and the cover plate 52 are bonded to eachother. The individual terminal 69 b is formed in a manner that theindividual terminal 69 b is inclined to be positioned outwardly in theX-direction as coming to the upper side from the CP-side individual pad69 a, and then the individual terminal 69 b extends to have astraight-line shape.

That is, when the actuator plate 51 and the cover plate 52 are bonded toeach other, the CP-side individual pad 69 a and the AP-side individualwiring 64 are electrically connected to each other. A plurality ofCP-side individual pads 69 a are arranged at a distance in theX-direction. The distance (array pitch) between two CP-side individualpads 69 a which are adjacent to each other is substantially constant.The plurality of CP-side individual pads 69 a and a plurality of CP-sidecommon pads 66 face each other one by one in the Z-direction. In otherwords, each of the CP-side individual pads 69 a and each of the CP-sidecommon pads 66 are disposed to be aligned on a straight line in theZ-direction.

The individual terminal 69 b extends to the upper end of the CP-sidetail portion 52 e on the outer side surface thereof in the Y-direction.Thus, the individual electrode 63 formed in the inner surface of each ofthe non-discharge channels 55 is electrically connected to the flexiblesubstrate 45 (see FIG. 5) on the individual terminal 69 b, through theAP-side individual wiring 64 and the CP-side individual pad 69 a.

A plurality of individual terminals 69 b are arranged to be spaced fromeach other in the X-direction. The distance (array pitch) between twoindividual terminals 69 b which are adjacent to each other issubstantially constant. The plurality of individual terminals 69 b arearranged between the plurality of common terminals 68 (common terminalgroups) which are arranged in the X-direction. The array pitch betweenthe individual terminals 69 b and the array pitch between the commonterminals 68 are substantially equal to each other.

The cover plate 52 is formed of a material which has insulatingproperties, and has thermal conductivity which is equal to or greaterthan that of the actuator plate 51. For example, in a case where theactuator plate 51 is formed of PZT, the cover plate 52 is preferablyformed of PZT or silicon. Thus, it is possible to reduce temperaturevariation in the actuator plate 51 and to cause the temperature of anink to be uniform. Thus, it is possible to cause a discharge speed of anink to be uniform and to improve printing stability.

Arrangement Relationship of Pair of Head Chips

As illustrated in FIG. 3, the head chips 40A and 40B are arranged to bespaced from each other in the Y-direction, in a state whereCP-side-Y-direction inner side surfaces 52 f 2 face each other in theY-direction.

The discharge channel 54 and the non-discharge channel 55 of the secondhead chip 40B are arranged so as to be shifted in the X-direction by thehalf pitch of the array pitch between the discharge channel 54 and thenon-discharge channel 55 of the first head chip 40A. That is, thedischarge channels 54 of the head chips 40A and 40B are arranged inzigzags, and the non-discharge channel 55 of the head chips 40A and 40Bare arranged in zigzags.

That is, as illustrated in FIG. 4, the discharge channel 54 of the firsthead chip 40A faces the non-discharge channel 55 of the second head chip40B in the Y-direction. As illustrated in FIG. 5, the non-dischargechannel 55 of the first head chip 40A faces the discharge channel 54 ofthe second head chip 40B in the Y-direction. The pitch between thechannels 54 and 55 in each of the head chips 40A and 40B may beappropriately changed.

Flow Passage Plate

The flow passage plate 41 is sandwiched between the first head chip 40Aand the second head chip 40B in the Y-direction. The flow passage plate41 is integrally formed of the same member. As illustrated in FIG. 3,the appearance of the flow passage plate 41 is a rectangular plate shapewhich is long in the X-direction and is short in the Z-direction. Whenviewed from the Y-direction, the appearance of the flow passage plate 41is substantially the same as the appearance of the cover plate 52.

The CP-side-Y-direction inner side surface 52 f 2 in the first head chip40A is bonded to a first main surface 41 f 1 (surface directed towardthe first head chip 40A side) of the flow passage plate 41 in theY-direction. The CP-side-Y-direction inner side surface 52 f 2 in thesecond head chip 40B is bonded to a second main surface 41 f 2 (surfacedirected toward the second head chip 40B side) of the flow passage plate41 in the Y-direction.

The flow passage plate 41 is formed of a material which has insulatingproperties, and has thermal conductivity which is equal to or greaterthan that of the cover plate 52. For example, in a case where the coverplate 52 is formed of silicon, the flow passage plate 41 is preferablyformed of silicon or carbon. Thus, it is possible to reduce temperaturevariation in the cover plate 52 between the head chips 40A and 40B.Therefore, it is possible to reduce temperature variation in theactuator plate 51 between the head chips 40A and 40B and to cause thetemperature of an ink to be uniform. Thus, it is possible to cause adischarge speed of an ink to be uniform and to improve printingstability.

An inlet flow passage 74 and an outlet flow passage 75 are formed ineach of the main surfaces 41 f 1 and 41 f 2 of the flow passage plate41. The inlet flow passage 74 individually communicates with the commonink room 71. The outlet flow passage 75 individually communicates withthe circulation passage 76 of the return plate 43.

The inlet flow passage 74 is recessed from each of the main surfaces 41f 1 and 41 f 2 of the flow passage plate 41 toward the inner sidethereof in the Y-direction. One end portion of the inlet flow passage 74in the X-direction is opened in one end surface of the flow passageplate 41 in the X-direction. The inlet flow passage 74 is inclined to bepositioned downwardly, as coming to the other end side thereof in theX-direction from one end surface of the flow passage plate 41 in theX-direction. Then, the inlet flow passage 74 is bent toward the otherend side thereof in the X-direction, and extends to have a straight-lineshape. As illustrated in FIG. 4, the width of the inlet flow passage 74in the Z-direction is substantially equal to the width of the common inkroom 71 in the Z-direction. The width of the inlet flow passage 74 inthe Z-direction may be equal to or smaller than the width of the commonink room 71 in the Z-direction.

The inlet flow passages 74 are arranged between the first head chip 40Aand the second head chip 40B in the Y-direction, so as to be spaced fromeach other in the Y-direction. That is, in the flow passage plate 41, aportion between the inlet flow passages 74 in the Y-direction ispartitioned by a wall member. Thus, pressure fluctuation in the channel,which occurs when an ink is discharged is blocked by the wall member.Accordingly, it is possible to suppress the occurrence of so-calledcrosstalk in which the pressure fluctuation propagates as a pressurewave, to another channel and the like through the flow passage betweenthe head chips 40A and 40B. Thus, it is possible to obtain excellentdischarge performance (printing stability).

As illustrated in FIG. 3, the outlet flow passage 75 is recessed fromeach of the main surfaces 41 f 1 and 41 f 2 of the flow passage plate 41toward the inner side thereof in the Y-direction, and is recessedupwardly from the lower end surface of the flow passage plate 41. Oneend portion of the outlet flow passage 75 is opened in the other endsurface of the flow passage plate 41 in the X-direction. The outlet flowpassage 75 is bent downward from the other end surface of the flowpassage plate 41 in the X-direction, so as to have a crank shape. Then,the outlet flow passage 75 extends toward the one end side thereof inthe X-direction, so as to have a straight-line shape. As illustrated inFIG. 4, the width of the outlet flow passage 75 in the Z-direction issmaller than the width of the inlet flow passage 74 in the Z-direction.The depth of the outlet flow passage 75 in the Y-direction issubstantially equal to the depth of the inlet flow passage 74 in theY-direction.

The outlet flow passage 75 is connected to the outlet manifold (notillustrated) on the other end surface of the flow passage plate 41 inthe X-direction. The outlet manifold is connected to the ink dischargetube 22 (see FIG. 1).

Outlet flow passages 75 are arranged between the first head chip 40A andthe second head chip 40B in the Y-direction, so as to be spaced fromeach other in the Y-direction. That is, in the flow passage plate 41, aportion between the outlet flow passages 75 in the Y-direction ispartitioned by a wall member. Thus, pressure fluctuation in the channel,which occurs when an ink is discharged is blocked by the wall member.Accordingly, it is possible to suppress the occurrence of so-calledcrosstalk in which the pressure fluctuation propagates as a pressurewave, to another channel and the like through the flow passage betweenthe head chips 40A and 40B. Thus, it is possible to obtain excellentdischarge performance (printing stability).

When the section in FIG. 4 is viewed, the inlet flow passage 74 and theoutlet flow passage 75 are not formed at a portion of the flow passageplate 41, which overlaps the CP-side tail portion 52 e in theY-direction. That is, the portion of the flow passage plate 41, whichoverlaps the CP-side tail portion 52 e in the Y-direction is set to bethe solid member. Thus, in comparison to a case the portion of the flowpassage plate 41, which overlaps the CP-side tail portion 52 e in theY-direction is set to be a hollow member, it is possible to avoid poorcrimping occurring by a space between members at a time of connection,when the flow passage plate 41 and the cover plate 52 are connected toeach other.

Inlet Manifold

As illustrated in FIG. 3, the inlet manifold 42 is collectively bondedto one end surface of the head chips 40A and 40B and the flow passageplate 41 in the X-direction. A supply passage 77 which communicates witheach of inlet flow passages 74 is formed in the inlet manifold 42. Thesupply passage 77 is recessed from the inner end surface of the inletmanifold 42 in the X-direction toward the outside thereof in theX-direction. The supply passage 77 collectively communicates with theinlet flow passages 74. The inlet manifold 42 is connected to the inksupply tube 21 (see FIG. 1).

Return Plate

The appearance of the return plate 43 is a rectangular plate shape whichis long in the X-direction and is short in the Y-direction. The returnplate 43 is collectively bonded to lower end surfaces of the head chips40A and 40B and the flow passage plate 41. In other words, the returnplate 43 is disposed on the opening end side of the discharge channels54 in the first head chip 40A and the second head chip 40B. The returnplate 43 is a spacer plate which is interposed between the opening endsof the discharge channels 54 in the first head chip 40A and the secondhead chip 40B, and the upper end of the nozzle plate 44. A plurality ofcirculation passages 76 that respectively connect the discharge channels54 in the head chips 40A and 40B to the outlet flow passage 75 areformed in the return plate 43. The plurality of circulation passages 76include first circulation passages 76 a and second circulation passages76 b. The plurality of circulation passages 76 penetrate the returnplate 43 in the Z-direction.

As illustrated in FIG. 4, the first circulation passages 76 a are formedat positions which are substantially the same as those of the dischargechannels 54 of the first head chip 40A in the X-direction, respectively.A plurality of first circulation passages 76 a are formed to be spacedfrom each other in the X-direction, corresponding to the array pitchbetween the discharge channels 54 in the first head chip 40A.

The first circulation passage 76 a extends in the Y-direction. The innerside end portion of the first circulation passage 76 a in theY-direction is positioned on an inner side from the CP-side-Y-directioninner side surface 52 f 2 of the first head chip 40A in the Y-direction.The inner side end portion of the first circulation passage 76 a in theY-direction communicates with the inside of the outlet flow passage 75.The outer side end portion of the first circulation passage 76 a in theY-direction individually communicates with the inside of thecorresponding discharge channel 54 in the first head chip 40A.

The cross-sectional area obtained when a portion of the dischargechannel 54 in the first head chip 40A, which faces the return plate 43is cut out at a plane which is orthogonal to the flowing direction of anink is referred to as “a channel-side flow passage cross-sectional area”below. Here, the portion of the discharge channel 54 in the first headchip 40A, which faces the return plate 43 means a portion (boundaryportion) at which the discharge channel 54 and the first circulationpassage 76 a are in contact with each other. That is, the channel-sideflow passage cross-sectional area means an opening area of a downstreamside end of the discharge channel 54 of the first head chip 40A in theflowing direction of an ink.

The cross-sectional area obtained when the first circulation passage 76a is cut out at a plane which is orthogonal to the flowing direction ofan ink is referred to as “a circulation passage-side flow passagecross-sectional area” below. That is, the circulation passage-side flowpassage cross-sectional area means a cross-sectional area when the firstcirculation passage 76 is cut out at a plane which is orthogonal to anextension direction of the first circulation passage 76.

In the embodiment, the circulation passage-side flow passagecross-sectional area is smaller than the channel-side flow passagecross-sectional area. Thus, in comparison to a case where thecirculation passage-side flow passage cross-sectional area is greaterthan the channel-side flow passage cross-sectional area, it is possibleto suppress the occurrence of so-called crosstalk in which pressurefluctuation in the channel, which occurs, for example, when an ink isdischarged propagates as a pressure wave, to another channel and thelike through the flow passage. Thus, it is possible to obtain excellentdischarge performance (printing stability).

As illustrated in FIG. 5, the second circulation passages 76 b areformed at positions which are substantially the same as those of thedischarge channels 54 of the second head chip 40B in the X-direction,respectively. A plurality of second circulation passages 76 b are formedto be spaced from each other in the X-direction, corresponding to thearray pitch between the discharge channels 54 in the second head chip40B.

The second circulation passage 76 b extends in the Y-direction. Theinner side end portion of the second circulation passage 76 b in theY-direction is positioned on an inner side from the CP-side-Y-directioninner side surface 52 f 2 of the second head chip 40B in theY-direction. The inner side end portion of the second circulationpassage 76 b in the Y-direction communicates with the inside of theoutlet flow passage 75. The outer side end portion of the secondcirculation passage 76 b in the Y-direction individually communicateswith the inside of the corresponding discharge channel 54 in the secondhead chip 40B.

Nozzle Plate

As illustrated in FIG. 3, the appearance of the nozzle plate 44 is arectangular plate shape which is long in the X-direction and is short inthe Y-direction. The appearance of the nozzle plate 44 is substantiallythe same as the appearance of the return plate 43. The nozzle plate 44is bonded to the lower end surface of the return plate 43. A pluralityof nozzle holes (ejection holes) 78 which penetrate the nozzle plate 44in the Z-direction are arranged in the nozzle plate 44. The plurality ofnozzle holes 78 includes first nozzle holes 78 a and second nozzle holes78 b. The plurality of nozzle holes 78 penetrate the nozzle plate 44 inthe Z-direction.

As illustrated in FIG. 4, the first nozzle holes 78 a are formed atportions of the nozzle plate 44, which face the first circulationpassages 76 a of the return plate 43 in the Z-direction, respectively.That is, the first nozzle holes 78 a are arranged on a straight line, soas to be spaced from each other in the X-direction and to have a pitchwhich is the same as that of the first circulation passages 76 a. Thefirst nozzle hole 78 a communicates with the inside of the firstcirculation passage 76 a at the outer end portion of the firstcirculation passage 76 a in the Y-direction. Thus, the first nozzle hole78 a communicates with the corresponding discharge channel 54 of thefirst head chip 40A through the corresponding first circulation passage76 a.

As illustrated in FIG. 5, the second nozzle holes 78 b are formed atportions of the nozzle plate 44, which face the second circulationpassages 76 b of the return plate 43 in the Z-direction, respectively.That is, the second nozzle holes 78 b are arranged on a straight line,so as to be spaced from each other in the X-direction and to have apitch which is the same as that of the second circulation passages 76 b.The second nozzle hole 78 b communicates with the inside of the secondcirculation passage 76 b at the outer end portion of the secondcirculation passage 76 b in the Y-direction. Thus, the second nozzlehole 78 b communicates with the corresponding discharge channel 54 ofthe second head chip 40B through the corresponding second circulationpassage 76 b.

Meanwhile, the non-discharge channel 55 does not communicate with thenozzle holes 78 a and 78 b, and is covered from a lower part by thereturn plate 43.

Operation Method of Printer

Next, an operation method of the printer 1 in a case where letters,figures, or the like are recorded on a recording medium P by using theprinter 1 will be described.

A state where the four ink tanks illustrated in FIG. 1 whichrespectively have sufficient inks of different colors are sealed isassumed as an initial state. A state where the ink jet head 5 is filledwith the inks in the ink tanks 4 through the ink circulation means 6 isassumed.

As illustrated in FIG. 1, if the printer 1 in the initial state isoperated, the grit rollers 11 and 13 of the transporting means 2 and 3rotate so as to transport a recording medium P in a transport direction(X-direction) between the grit rollers 11 and 13, and the pinch rollers12 and 14. Simultaneous with transporting of the recording medium P, thedriving motor 38 rotates the pulleys 35 and 36 so as to operate theendless belt 37. Thus, the carriage 33 moves with reciprocating, in theY-direction while being guided by the guide rails 31 and 32.

Since the inks of four colors are appropriately discharged to therecording medium P by the ink jet heads 5 during a period when thecarriage 33 moves with reciprocating, letters, an image, or the like canbe recorded on a recording medium P.

Here, motion of each of the ink jet heads 5 will be described.

In a vertical circulation type ink jet head 5 in the edge shoot type asin the embodiment, firstly, the pressure pump 24 and the suction pump 25illustrated in FIG. 2 are operated, and thus an ink is caused to flow inthe circulation flow passage 23. In this case, the ink flowing in theink supply tube 21 flows into each of the inlet flow passages 74 of theflow passage plate 41, through the supply passage 77 of the inletmanifold 42 illustrated in FIG. 3. The ink flowing into each of theinlet flow passages 74 passes through the common ink room 71. Then, theink is supplied into the discharge channels 54 through the slits 72,respectively. The ink flowing into the discharge channels 54 arecollected in the outlet flow passage 75 through the circulation passage76 of the return plate 43. Then, the ink is discharged to the inkdischarge tube 22 illustrated in FIG. 2, through the outlet manifold(not illustrated). The ink discharged to the ink discharge tube 22 isbrought back to the ink tank 4. Then, the ink is supplied to the inksupply tube 21 again. Thus, the ink is circulated between the ink jethead 5 and the ink tank 4.

If moving with reciprocating is started by the carriage 33 (see FIG. 1),a driving voltage is applied to the electrodes 61 and 63 via theflexible substrate 45. At this time, the driving voltage is appliedbetween the electrodes 61 and 63, in a state where the individualelectrode 63 is set to have a driving potential Vdd and the commonelectrode 61 is set to have a reference potential GND. If the voltage isapplied, thickness shear deformation occurs in two drive walls 56 thatdefine the discharge channel 54. Thus, the two drive walls 56 aredeformed to protrude toward the non-discharge channel 55 side. That is,since two piezoelectric substrates which are polarized in the thicknessdirection (Y-direction) are stacked, if the driving voltage is applied,the actuator plate 51 in the embodiment is deformed and bent to have aV-shape by using the intermediate position of the drive wall 56 in theY-direction, as the center. Thus, the discharge channel 54 deforms as itexpands, for example.

If the volume of the discharge channel 54 is increased by thedeformation of the two drive walls 56, an ink in the common ink room 71is guided into the discharge channel 54 through the corresponding slits72. The ink guided into the discharge channel 54 propagates in thedischarge channel 54 in a form of a pressure wave. The driving voltageapplied between the electrodes 61 and 63 reaches the zero at a timingwhen the pressure wave reaches the nozzle hole 78.

Thus, the drive wall 56 is restored, and the volume of the dischargechannel 54, which has been temporarily increased returns to the originalvolume. With this operation, pressure in the discharge channel 54 isincreased, and thus the ink is pressurized. As a result, it is possibleto discharge the ink from the nozzle hole 78. At this time, when the inkpasses through the nozzle hole 78, the ink is discharged in a form of anink droplet having a droplet shape. Thus, as described above, letters,an image, or the like can be recorded on the recording medium P.

The operation method of the ink jet head 5 is not limited to theabove-described details. For example, a configuration in which the drivewall 56 in a normal state is deformed to the inner side of the dischargechannel 54, and thus the discharge channel 54 is, for example, recessedtoward the inner side thereof may be made. In this case, thisconfiguration may be realized by setting the voltage applied between theelectrodes 61 and 63 to a voltage reversed to the above-describedvoltage, or by setting the polarization direction of the actuator plate51 to be reversed without changing the applied direction of the voltage.In addition, a pressurized force of an ink when being discharged mayincrease in a manner that the discharge channel 54 is deformed bulgingoutwardly, and then deforms recessed to the inner side.

Manufacturing Method of Ink Jet Head

Next, a manufacturing method of the ink jet head 5 will be described.The manufacturing method of the ink jet head 5 in the embodimentincludes a head chip production step, a flow-passage plate productionstep, a various-plate bonding step, and a return-plate-and-like bondingstep. The head chip production step may be performed for the head chips40A and 40B, by using the similar method. Thus, in the followingdescriptions, the head chip production step for the first head chip 40Awill be described.

Head Chip Production Step

In the embodiment, the head chip production step includes a waferpreparation step, a mask pattern forming step, a channel forming step,and an electrode forming step, as steps on the actuator plate side.

As illustrated in FIG. 9, in the wafer preparation step, firstly, twopiezoelectric wafers 110 a and 110 b which are polarized in a thicknessdirection (Y-direction) are stacked in a state where a polarizationdirection is set to be a reverse direction. Thus, a Chevron typeactuator wafer 110 is formed.

Then, the front surface (one piezoelectric wafer 110 a) of the actuatorwafer 110 is ground. In the embodiment, a case where the piezoelectricwafers 110 a and 110 b having the same thickness are stuck to each otheris described. However, piezoelectric wafers 110 a and 110 b having athickness different from each other may be stuck to each other inadvance.

As illustrated in FIG. 10, in the mask pattern forming step, a maskpattern 111 used in the electrode forming step is formed. Specifically,a mounting tape 112 is put on the back surface of the actuator wafer110. Then, a mask material such as a photosensitive dry film is put onthe front surface of the actuator wafer 110. Then, patterning isperformed on the mask material by using a photolithography technology,and thus a partial mask material of the mask material, which ispositioned in a region for forming the AP-side common pad 62 and theAP-side individual wiring 64 (see FIG. 7) which are described above isremoved. Thus, the mask pattern 111 in which at least the region forforming the AP-side common pad 62 and the AP-side individual wiring 64is opened is formed on the front surface of the actuator wafer 110. Inthis case, the mask pattern 111 covers a portion of the actuator wafer110, except for the region for forming the AP-side common pad 62 and theAP-side individual wiring 64. The mask material may be formed, forexample, by coating the front surface of the actuator wafer 110.

As illustrated in FIG. 11, in the channel forming step, cutting isperformed on the front surface of the actuator wafer 110 by a dicingblade and the like (not illustrated). Specifically, as illustrated inFIG. 12, the plurality of channels 54 and 55 are formed on the frontsurface of the actuator wafer 110, so as to be arranged in parallel at adistance in the X-direction. In this case, a region for forming each ofthe channels 54 and 55, on the front surface of the actuator wafer 110,is cut out in accordance with the above-described mask pattern 111.

Specifically, in the channel forming step, the plurality of channels 54and 55 are formed in the actuator wafer 110 so as to be arranged at adistance in the X-direction. The channels 54 and 55 include theextension portions 54 a and 55 a (see FIG. 4) which extend in theZ-direction, and the raise-and-cut portions 54 b and 55 b (see FIG. 4)which continue from the extension portions 54 a and 55 a toward one sideof the Z-direction, and has a groove depth which is gradually reducedtoward the one side of the Z-direction are formed.

The order of the steps in the mask pattern forming step and the channelforming step which are described above may be reversed so long as themask pattern 111 can be formed to have a desired shape. In theabove-described mask pattern forming step, the mask material at aportion positioned in a region of forming the discharge channels 54 andthe non-discharge channels 55 may be removed in advance.

The electrode forming step includes a degreasing step, an etching step,a lead leaching step, a catalyst impartation step, a mask removal step,a plating step, and a plating film removal step.

In the degreasing step, contaminants such as oils and fats, which areattached to the actuator wafer 110 are removed.

In the etching step, the actuator wafer 110 is etched by an ammoniumfluoride solution or the like. Thus, an adhesive force between a platingfilm formed in the plating step, and the actuator wafer 110 is improved.

In the lead leaching step, in a case where the actuator wafer 110 isformed of PZT, lead in the front surface of the actuator wafer 110 isremoved. Thus, a catalyst suppression effect of lead on the surface ofthe actuator wafer 110 is suppressed.

For example, the catalyst impartation step is performed by a sensitizerand activator method. As illustrated in FIG. 13, in the sensitizer andactivator method, firstly, a sensitization treatment in which theactuator wafer 110 is immersed in a stannous chloride aqueous solutionso as to cause stannous chloride to be attracted to the actuator wafer110 is performed. Then, the actuator wafer 110 is lightly washed byrinsing or the like. Then, the actuator wafer 110 is immersed in apalladium chloride aqueous solution, so as to cause palladium chlorideto be attracted to the actuator wafer 110. If the immersing isperformed, an oxidation-reduction reaction occurs between palladiumchloride attracted to the actuator wafer 110 and stannous chloride whichhas been attracted in the above-described sensitization treatment. Thus,metal palladium as a catalyst 113 is precipitated (activatingtreatment). The catalyst impartation step may be performed plural numberof times.

The catalyst impartation step may be performed by a method other thanthe above-described sensitizer and activator method. For example, thecatalyst impartation step may be performed by a catalyst acceleratormethod. In the catalyst accelerator method, the actuator wafer 110 isimmersed in a colloidal solution of tin and palladium. Then, theactuator wafer 110 is immersed in an acidic solution (for example,hydrochloric acid solution) so as to be activated. Thus, metal palladiumis precipitated on the front surface of the actuator wafer 110.

Then, as illustrated in FIG. 14, in the mask removal step, the maskpattern 111 formed on the front surface of the actuator wafer 110 isremoved, for example, by lifting-off. A portion of the catalyst 113,which is imparted onto the mask pattern 111 is removed along with themask pattern 111. That is, in the embodiment, the catalyst 113 remainsonly at a portion of the actuator wafer 110, which is exposed from themask pattern 111 (inner surface of each of the channels 54 and 55, theregion for forming the AP-side common pad 62 and the AP-side individualwiring 64, and the like). The mask removal step may be performed afterthe plating step.

As illustrated in FIG. 15, in the plating step, the actuator wafer 110is immersed in a plating solution. If the actuator wafer 110 is immersedin a plating solution, a metal film 114 is formed at the portion of theactuator wafer 110, onto which the catalyst 113 is imparted, byprecipitation. As electrode metal used in the plating step, for example,Ni (nickel), Co (cobalt), Cu (copper), Au (gold), and the like arepreferable. In particular, Ni is preferably used.

As illustrated in FIG. 16, in the plating film removal step, a portionof the metal film 114 (see FIG. 15), which is positioned on the bottomsurface of the non-discharge channel 55 is removed. Specifically,scanning with a laser beam L is performed in the Z-direction, in a statewhere the bottom surface of the non-discharge channel 55 is irradiatedwith the laser beam L. If the scanning is performed, a portion of themetal film 114 (see FIG. 15), which is irradiated with the laser beam Lis selectively removed. Thus, the metal film 114 (see FIG. 15) isdivided by the bottom surface of the non-discharge channel 55.Accordingly, in the actuator wafer 110, the common electrode 61 and theindividual electrode 63 are respectively formed on the inner surfaces ofthe channels 54 and 55, respectively. The AP-side common pad 62 and theAP-side individual wiring 64 (see FIG. 7) which are connected to thecorresponding common electrode 61 and to the corresponding individualelectrode 63 are formed on the front surface of the actuator wafer 110.

Instead of the laser beam L, a dicer may be used. The plating filmremoval step is not limited to removing of the portion of the metal film114, which is positioned on the bottom surface of the non-dischargechannel 55. For example, in a catalyst removal step, a portion of thecatalyst 113, which is positioned on the bottom surface of thenon-discharge channel 55 may be removed. Specifically, in the catalystremoval step, scanning with a laser beam L may be performed in theZ-direction, in a state where the bottom surface of the non-dischargechannel 55 is irradiated with the laser beam L. Thus, the portion of thecatalyst 113, which is irradiated with the laser beam L may beselectively removed.

Then, the mounting tape 112 is peeled off, and the actuator wafer 110 isfragmented by using a dicer or the like. Accordingly, theabove-described actuator plate 51 (see FIG. 5) is completed.

In the embodiment, the head chip production step includes a common inkroom forming step, a slit forming step, a through-hole forming step, arecess portion forming step, and an electrode-and-wiring forming step,as steps of the cover plate side.

As illustrated in FIG. 17, in the common ink room forming step, sandblasting or the like is performed on a cover wafer 120 from the frontsurface side, through a mask (not illustrated), and thereby the commonink room 71 is formed.

As illustrated in FIG. 18, in the slit forming step, sand blasting orthe like is performed on the cover wafer 120 from the back surface side,through a mask (not illustrated), and thereby slits 72 whichindividually communicate with the inside of the common ink room 71 areformed.

As illustrated in FIG. 17, in the through-hole forming step, sandblasting or the like is performed on a cover wafer 120 from the frontsurface side, through a mask (not illustrated), and thereby a frontsurface-side through-recess portion 85 a is formed. The step of forminga front surface-side through-recess portion 85 a may be performed in astep which is the same as the common ink room forming step.

As illustrated in FIG. 18, in the through-hole forming step, sandblasting or the like is performed on the cover wafer 120 from the backsurface side, through a mask (not illustrated), and thereby a backsurface-side through-recess portion 85 b which individually communicateswith the inside of the front surface-side through-recess portion 85 a isformed. As described above, the front surface-side through-recessportion 85 a is caused to communicate with the back surface-sidethrough-recess portion 85 b, and thereby the through-hole 85 is formedin the cover wafer 120. The step of forming a back surface-sidethrough-recess portion 85 b may be performed in a step which is the sameas the slit forming step.

In the recess portion forming step, as illustrated in FIG. 17, sandblasting or the like is performed on the cover wafer 120 from the frontsurface side or the back surface side, through a mask (not illustrated),and thereby the slit 121 for forming the recess portion 73 (see FIG. 7)is formed. Then, cover wafer 120 is fragmented along an axis of the slit121 by using a dicer or the like. Accordingly, the recess portion 73 isformed in the cover wafer 120. Thus, the cover plate 52 (see FIG. 3) inwhich the recess portion 73 is formed is completed.

Each of the common ink room forming step, the slit forming step, thethrough-hole forming step, and the recess portion forming step is notlimited to sand blasting, and may be performed by dicing, cutting, orthe like.

Then, as illustrated in FIG. 19, in the electrode-and-wiring formingstep, various electrodes and wirings such as the in-through-holeelectrode 86, the CP-side common pad 66, the common lead wiring 67, thejoint common electrode 82 (see FIG. 20), and the CP-side individualwiring 69 are formed in the cover plate 52.

Specifically, in the electrode-and-wiring forming step, as illustratedin FIG. 20, firstly, a mask (not illustrated) is disposed on the entiresurface (including the front surface, the back surface, the upper endsurface, a surface in which the recess portion 73 is formed, and asurface in which the through-hole 85 is formed) of the cover plate 52.In the mask, regions for forming various electrodes and various wirings(in-through-hole electrode 86, CP-side common pad 66, common lead wiring67, joint common electrode 82, and CP-side individual wiring 69) areopened. Then, a film of an electrode material is formed on the entiresurface of the cover plate 52 by electroless plating or the like. Thus,the film of the electrode material, which will function as the variouselectrodes and the various wirings is formed on the entire surface ofthe cover plate 52 through openings of the mask. As the mask, forexample, a photosensitive dry film or the like may be used. Theelectrode-and-wiring forming step is not limited to plating, and may beperformed by vapor deposition and the like. In a step of forming thein-through-hole electrode 86, the in-through-hole electrode 86 may beformed by filling the through-hole 85 with a conductive paste or thelike.

After the electrode-and-wiring forming step ends, the mask is removedfrom the entire surface of the cover plate 52.

The actuator plates 51 are bonded to the cover plates 52, and therebythe head chips 40A and 40B are produced. Specifically, theAP-side-Y-direction inner side surface 51 f 1 is stuck to theCP-side-Y-direction outer side surface 52 f 1.

Flow-passage Plate Production Step

In the embodiment, the flow-passage plate production step includes aflow passage forming step and a fragmentation step.

As illustrated in FIG. 21, in the flow passage forming step (flowpassage forming step of the front surface side), firstly, sand blastingor the like is performed on a flow passage wafer 130 from the frontsurface side, through a mask (not illustrated), and thereby the inletflow passage 74 and the outlet flow passage 75 are formed.

In addition, in the flow passage forming step (flow passage forming stepof the back surface side), sand blasting or the like is performed on theflow passage wafer 130 from the back surface side, through a mask (notillustrated), and thereby the inlet flow passage 74 and the outlet flowpassage 75 are formed. Each of the steps in the flow passage formingstep is not limited to sand blasting, and may be performed by dicing,cutting, and the like.

Then, in the fragmentation step, the flow passage wafer 130 isfragmented by using a dicer or the like. The fragmentation is performedalong an axis (virtual line D) of a straight-line portion of the outletflow passage 75 in the X-direction. Thus, the flow passage plate 41 (seeFIG. 3) is completed.

Various-Plate Bonding Step

Then, as illustrated in FIG. 22, in the various-plate bonding step, thecover plates 52 in the head chips 40A and 40B are bonded to the flowpassage plate 41. Specifically, the outer side surfaces (main surfaces41 f 1 and 41 f 2) of the flow passage plate 41 in the Y-direction arestuck to CP-side-Y-direction inner side surfaces 52 f 2 of the headchips 40A and 40B.

Thus, a plate bonded body 5A is produced.

After all the plates in a wafer state are stuck to each other, chipdivision (fragmentation) may be performed.

Return-Plate-and-Like Bonding Step

Then, the return plate 43 and the nozzle plate 44 are bonded to theplate bonded body 5A. Then, the flexible substrate 45 (see FIG. 4) ismounted on the CP-side tail portion 52 e.

With the above steps, the ink jet head 5 in the embodiment is completed.

As described above, each of the head chips 40A and 40B in the embodimentincludes the actuator plate 51 and the in-channel electrodes 61 and 63.In the actuator plate 51, a plurality of channels 54 and 55 are arrangedat a distance in the X-direction. The channels 54 and 55 include theextension portions 54 a and 55 a which extend in the Z-direction, andthe raise-and-cut portions 54 b and 55 b which continue from theextension portions 54 a and 55 a toward one side of the Z-direction andhas a groove depth which is gradually reduced toward the one side of theZ-direction. The in-channel electrodes 61 and 63 are formed on the innersurface of each of the channels 54 and 55, with a plating film.

According to the examination of the inventors, a not-precipitated placemay be provided in the plating film or a plating lump may be formed, inaccordance with the shape of the channel (groove) in which an electrodeis formed. In particular, in a case where the plurality of channels isconfigured by a channel which has a cut-off shape and includes only anextension portion which extends in the first direction, and a channelwhich includes a raise-and-cut portion, it is clear that anot-precipitated place is easily provided in the plating film or aplating lump is easily formed. The reason is as follows. Regardingrinsing for removing a catalyst which becomes unnecessary after thecatalyst is imparted, the degree of the catalyst being removed variesdepending on the shape of a plating target. Thus, if a condition forimparting the catalyst is adjusted in accordance with one shape, in aplating target having another shape, the required amount of the catalystbecomes insufficient by excessive rinsing, and thus a not-precipitatedplace may be provided in a plating film. Otherwise, a plating lump maybe formed by insufficient rinsing. Therefore, in a case where anelectrode is formed by plating, it is considered that a condition forperforming plating on a target having a plurality of different shapes isdifficult. This state becomes more significant, if nozzle density isincreased and thus a groove width is reduced (for example, being equalto or smaller than 100 μm).

As a result of the close research, the inventors found the followingsand achieved the present invention. That is, the frequency of anot-precipitated place being provided in a plating film or a platinglump being formed has high correlation with the shape of a channel.Thus, if the shapes of a plurality of channels are set to be shapeshaving a common portion, it is possible to suppress an occurrence of asituation in which a not-precipitated place is provided in a platingfilm or a plating lump is formed.

According to the embodiment, the plurality of channels 54 and 55includes the extension portions 54 a and 55 a which extend in theZ-direction, and the raise-and-cut portions 54 b and 55 b which continuefrom the extension portions 54 a and 55 a toward one side of theZ-direction and has a groove depth which is gradually reduced toward theone side of the Z-direction. Thus, the shapes of the plurality ofchannels 54 and 55 have a common portion. The in-channel electrodes 61and 63 are formed with a plating film, on inner surfaces of theplurality of channels 54 and 55 having shapes which have a commonportion. Thus, it is possible to suppress the occurrence of a situationin which a not-precipitated place is provided in a plating film or aplating lump is formed, in a plating electrode.

From a viewpoint of suppressing providing of a not-precipitated place ina plating film and forming of a plating lump, it is considered that eachof the plurality of channels is set to be a channel having a cut-offshape. However, in a case where each of the plurality of channels is setto be a channel having a cut-off shape, cracks or chipping may occur inan actuator plate, in a step of forming a plating electrode.

On the contrary, according to the embodiment, the plurality of channels54 and 55 include the raise-and-cut portions 54 b and 55 b. Thus, incomparison to a case where each of the plurality of channels is set tobe a channel having a cut-off shape, this configuration is structurallyrobust. Accordingly, it is possible to suppress an occurrence of asituation in which cracks or chipping occurs in the actuator wafer 110,in the step of forming a plating electrode.

In the embodiment, the plurality of channels 54 and 55 have shapes whichare different from each other.

The shapes of a plurality of channels may be different from each other,in accordance with a type of ejecting a liquid from the plurality ofchannels. For example, the plurality of channels may be configured by achannel having a cut-off shape and a channel which includes araise-and-cut portion. However, in this case, it is clear that anot-precipitated place is easily provided in a plating film or a platinglump is easily formed.

On the contrary, according to the embodiment, even in a case where theshapes of the plurality of channels 54 and 55 are different from eachother, it is possible to suppress the occurrence of a situation in whicha not-precipitated place is provided in a plating film or a plating lumpis formed, in a plating electrode, because the plurality of channels 54and 55 include the raise-and-cut portions 54 b and 55 b. In addition, itis possible to suppress the occurrence of a situation in which cracks orchipping occurs in the actuator plate 51.

In the embodiment, the plurality of channels 54 and 55 include thedischarge channels 54 and the non-discharge channels 55 which arealternately arranged at a distance in the X-direction. The in-channelelectrodes 61 and 63 are the common electrode 61 formed on the innersurface of each of the discharge channels 54 and the individualelectrode 63 formed on the inner surface of each of the non-dischargechannels 55. The length of the non-discharge channel 55 in theZ-direction may be longer than the length of the discharge channel 54 inthe Z-direction.

According to the embodiment, in a type in which an ink is dischargedfrom only the discharge channels 54 among the plurality of channels 54and 55, it is possible to suppress the occurrence of a situation inwhich a not-precipitated place is provided in a plating film or aplating lump is formed, in a plating electrode. In addition, it ispossible to suppress the occurrence of a situation in which cracks orchipping occurs in the actuator plate 51.

In the embodiment, the cover plate 52 which is stacked on theAP-side-Y-direction inner side surface 51 f 1 so as to close thedischarge channels 54 and the non-discharge channels 55 and in which theliquid supply passage 70 which communicates with the discharge channels54 and the through-hole 85 which penetrates the cover plate 52 in theY-direction and is disposed at a place in which the liquid supplypassage 70 is not formed are formed, and the connection wiring 60 whichconnects the common electrode 61 to the flexible substrate 45 throughthe through-hole 85 in the cover plate 52 are further included.

According to the embodiment, the through-hole 85 which penetrates thecover plate 52 in the Y-direction and is disposed at a place in whichthe liquid supply passage 70 is not formed is formed in the cover plate52. The connection wiring 60 connects the common electrode 61 to theflexible substrate 45 through the through-hole 85. Thus, in comparisonto a case where the common electrode 61 is formed in a flow passage foran ink, it is possible to reduce an occurrence of an electrode beingprovided in a place having a probability of the electrode beingcorroded. Accordingly, it is possible to suppress corrosion of anelectrode due to a liquid such as an ink, and to improve reliability. Inaddition, in comparison to a case where the common electrode 61 isformed in a flow passage for an ink, it is possible to increase choicesfor electrode metal. For example, it is possible to use metal (forexample, copper and silver) which is corroded by a liquid such as anink, for the connection wiring (electrode) 60. In addition, it ispossible to secure an area of a region in which the connection wiring 60can be formed, without being influenced by grooves such as the dischargechannels 54 and the non-discharge channels 55. In particular, in theconfiguration in which the discharge channels 54 and the non-dischargechannels 55 are formed in the actuator plate 51, a region of forming thechannels can easily be complicated in comparison to a configuration inwhich only the ejection channels are formed. Thus, this is advantageousin that strength at a connection portion between various wirings issecured and the degree of freedom of layouts for the various wirings isimproved. In addition, since the connection wiring 60 connects thecommon electrode 61 to the flexible substrate 45, in the cover plate 52,it is possible to suppress an increase of electrostatic capacity byseparating the connection wiring 60 from the electrode on the actuatorplate 51 side, in comparison to a configuration in which the connectionwiring 60 is disposed on the actuator plate 51 side.

In the embodiment, the connection wiring 60 is formed at the CP-sidetail portion 52 e, in the stacked state of the actuator plate 51 and thecover plate 52.

According to the embodiment, it is possible to secure a wide area of theregion in which the connection wiring 60 can be formed, in the CP-sidetail portion 52 e. Accordingly, it is easy to secure strength at aconnection portion between various wirings, and to improve the degree offreedom of layouts for the various wirings.

In the embodiment, the connection wiring 60 includes the in-through-holeelectrode 86 formed on the inner surface of the through-hole 85 and thecommon lead wiring 67 which connects the in-through-hole electrode 86 tothe flexible substrate 45 at the CP-side tail portion 52 e.

According to the embodiment, it is possible to electrically connect thecommon electrode 61 to the flexible substrate 45 at a position whichavoids the liquid supply passage 70, through the in-through-holeelectrode 86 and the common lead wiring 67. Therefore, it is possible toavoid an occurrence of a situation in which the connection wiring 60 isbrought into contact with a liquid such as an ink, which flows in theliquid supply passage 70.

In the embodiment, the common lead wiring 67 includes a common terminal68 which is divided so as to be formed in at least three or more placesin the X-direction, on the outer side surface of the CP-side tailportion 52 e in the Y-direction. The common terminal 68 is connected tothe flexible substrate 45.

According to the embodiment, since the common terminal 68 is formed onthe outer side surface of the CP-side tail portion 52 e in theY-direction, it is possible to easily perform crimping work between theflexible substrate 45 and the common terminal 68, in comparison to acase where the common terminal 68 is formed on the CP-side-Y-directioninner side surface 52 f 2. In addition, since the common terminal 68 isdivided so as to be formed in at least three or more places in theX-direction, it is possible to suppress an occurrence of dullness of adriving pulse, which occurs by a difference of a nozzle position in theX-direction, in comparison to a case where the common terminal 68 ispartially formed (for example, at both ends of the cover plate in theX-direction).

In the embodiment, the plurality of AP-side common pads 62 which extendfrom the common electrode 61 and are disposed to be spaced from eachother in the X-direction are formed on the inner side surface of theAP-side tail portion 51 e in the Y-direction. The plurality of CP-sidecommon pads 66 which extend from the in-through-hole electrode 86, aredisposed to be spaced from each other in the X-direction, andrespectively face the AP-side common pads 62 in the Y-direction areformed around the through-hole 85 on the CP-side-Y-direction outer sidesurface 52 f 1.

According to the embodiment, when the actuator plate 51 and the coverplate 52 are bonded to each other, the AP-side common pad 62 can beconnected to the CP-side common pad 66. Thus, it is possible to easilyconnect the common electrode 61 and the flexible substrate 45 via thepads 62 and 66 and the like. In addition, the common electrode 61 formedon the inner surface of each of the plurality of discharge channels 54is conducted to the in-through-hole electrode 86 via the CP-side commonpad 66 from the AP-side common pad 62, and the lead wiring 67 connectedto the in-through-hole electrode 86 extends up to the CP-side tailportion 52 e. Thus, it is possible to easily perform electrodearrangement of the common electrode 61 and the individual electrode 63.

In the embodiment, the AP-side individual wiring 64 which extends in theX-direction and connects individual electrodes 63 which face each otherwith the discharge channel 54 interposed between the individualelectrodes 63 is formed on the inner side surface of the AP-side tailportion 51 e in the Y-direction. The CP-side individual wiring 69 whichis divided in the X-direction in one end portion in the Z-direction isformed on the CP-side-Y-direction outer side surface 52 f 1. The CP-sideindividual wiring 69 includes the CP-side individual pad 69 a whichfaces the AP-side individual wiring 64 in the Y-direction, and theindividual terminal 69 b which extends upwardly from the CP-sideindividual pad 69 a.

According to the embodiment, when the actuator plate 51 and the coverplate 52 are bonded to each other, the AP-side individual wiring 64 canbe connected to the CP-side individual pad 69 a. Thus, it is possible toeasily connect the individual electrode 63 to the flexible substrate 45via the individual wirings 64 and 69, the individual pad 69 a, and thelike. In the embodiment, both of the individual terminal 69 b and thecommon terminal 68 are formed on the CP-side-Y-direction outer sidesurface 52 f 1. Thus, in comparison to a case where the individualterminal 69 b and the common terminal 68 are formed on the surfaces ofthe cover plate 52, which are different from each other, it is possibleto easily perform crimping work between the individual terminal 69 b andthe common terminal 68, and the flexible substrate 45.

In the embodiment, the plurality of recess portions 73 which arerecessed toward the inside of the cover plate 52 and are arranged to bespaced from each other in the X-direction are formed at the upper end ofthe CP-side tail portion 52 e. The common lead wiring 67 is connected tothe in-through-hole electrode 86 and the flexible substrate 45 along therecess portion 73.

According to the embodiment, in comparison to a case where the commonlead wiring 67 is connected to the in-through-hole electrode 86 and theflexible substrate 45 through a through-hole 90 (see FIG. 24) which willbe described later, it is possible to reduce the length of the headchips 40A and 40B in the Z-direction because it is sufficient that arecess-portion forming region (for example, a region of forming the slit121 illustrated in FIG. 17) which is smaller than a through-hole formingregion (for example, a region of forming the through-hole 90 illustratedin FIG. 24) is formed in the cover plate 52. Therefore, it is possibleto reduce the size of each of the head chips 40A and 40B, and toincrease the number of pieces taken from a wafer having a predeterminedsize.

In the embodiment, the ink jet head 5 includes the head chips 40A and40B.

According to the embodiment, in the ink jet head 5 which includes thehead chips 40A and 40B, it is possible to suppress the occurrence of asituation in which a not-precipitated place is provided in a platingfilm or a plating lump is formed, in a plating electrode. In addition,it is possible to suppress the occurrence of a situation in which cracksor chipping occurs in the actuator plate 51.

In the embodiment, a pair of head chips 40A and 40B is disposed to faceCP-side-Y-direction inner side surfaces 52 f 2 to each other in theY-direction are provided. The flow passage plate 41 is disposed betweenthe pair of head chips 40A and 40B. The inlet flow passage 74 whichcommunicates with liquid supply passages 70 of the pair of cover plates52 is formed in the flow passage plate 41.

According to the embodiment, in each of the head chips 40A and 40B, theCP-side-Y-direction outer side surface 52 f 1 can be exposed to theoutside thereof in the Y-direction. Thus, it is possible to easilyconnect the flexible substrate 45 to the connection wiring 60 in thetwo-row type ink jet head 5.

In the embodiment, each of the plurality of discharge channels 54 isopened in the lower end surface of the of the actuator plate 51 in eachof the pair of head chips 40A and 40B. The nozzle plate 44 which hasnozzle holes 78 which respectively communicate with the dischargechannels 54 is disposed on the lower end surface of each of the pair ofactuator plates 51. The return plate 43 which has the circulationpassages 76 which cause the discharge channels 54 to respectivelycommunicate with the nozzle holes 78 is disposed between the pair ofactuator plates 51 and the nozzle plate 44 in the Z-direction. Theoutlet flow passage 75 which communicates with the circulation passage76 is formed in the flow passage plate 41.

According to the embodiment, it is possible to circulate a liquidbetween each of the discharge channels 54 and the ink tank 4. Thus, itis possible to suppress staying of bubbles in the vicinity of the nozzlehole 78 in the discharge channel 54.

The printer 1 according to the embodiment includes the above-describedink jet head 5, and moving mechanisms 2, 3, and 7 that relatively movethe ink jet head 5 and a recording medium P.

According to the embodiment, in the printer 1 which includes the ink jethead 5, it is possible to suppress the occurrence of a situation inwhich a not-precipitated place is provided in a plating film or aplating lump is formed, in a plating electrode. In addition, it ispossible to suppress the occurrence of a situation in which cracks orchipping occurs in the actuator plate 51.

The manufacturing method of the head chips 40A and 40B in the embodimentincludes the channel forming step of forming the plurality of channels54 and 55 (which include the extension portions 54 a and 55 a whichextend in the Z-direction and the raise-and-cut portions 54 b and 55 bwhich continue from the extension portions 54 a and 55 a toward one sideof the Z-direction and has a groove depth which is gradually reducedtoward the one side of the Z-direction) in the actuator wafer 110 so asto be arranged at a distance in the X-direction, and the electrodeforming step of forming a plating film as the in-channel electrodes 61and 63, on the inner surfaces of the channels 54 and 55, after thechannel forming step.

According to this method, in the channel forming step, the plurality ofchannels 54 and 55 which include the extension portions 54 a and 55 awhich extend in the Z-direction, and the raise-and-cut portions 54 b and55 b which continue from the extension portions 54 a and 55 a toward oneside of the Z-direction and has a groove depth which is graduallyreduced toward the one side of the Z-direction are formed. Thus, theshapes of the plurality of channels 54 and 55 have a common portion. Inthe electrode forming step, the plating film is formed as the in-channelelectrodes 61 and 63, in the inner surfaces of the plurality of channels54 and 55 having shapes which have a common portion. Thus, it ispossible to suppress the occurrence of a situation in which anot-precipitated place is provided in a plating film or a plating lumpis formed, in a plating electrode. In addition, since the plurality ofchannels 54 and 55 respectively includes the raise-and-cut portions 54 band 55 b, this configuration is structurally robust, in comparison to acase where each of the plurality of channels is set to be a channelhaving a cut-off shape. Accordingly, it is possible to suppress anoccurrence of a situation in which cracks or chipping occurs in theactuator wafer 110, in the electrode forming step.

The technical range of the present invention is not limited to theabove-described embodiment. Various modifications may be added in arange without departing from the gist of the present invention.

For example, in the above-described embodiment, as an example of theliquid ejecting apparatus, the ink jet printer 1 is described as anexample. However, it is not limited to the printer. For example, a faxmachine, an on-demand printer, and the like may be used as the liquidejecting apparatus.

In the above-described embodiment, the two-row type ink jet head 5 inwhich two rows of nozzle holes 78 are arranged is described. However, itis not limited thereto. For example, an ink jet head 5 in which thenumber of rows of nozzle holes is equal to or greater than three may beprovided, or an ink jet head 5 in which one row of nozzle holes isarranged may be provided.

In the above-described embodiment, among edge shoot type heads, acirculation type in which an ink is circulated between the ink jet head5 and the ink tank 4 is described. However, it is not limited thereto.For example, the present invention may be applied to a so-called sideshoot type ink jet head in which an ink is discharged from the centerportion of a discharge channel in a channel extension direction.

In the above-described embodiment, a configuration in which thedischarge channels 54 and the non-discharge channels 55 are alternatelyarranged is described. However, it is not limited to only thisconfiguration. For example, the present invention may be applied to aso-called three-cycle type ink jet head in which an ink is dischargedfrom all channels in order.

In the above-described embodiment, a configuration in which the Chevrontype is used as the actuator plate is described. However, it is notlimited thereto. That is, an actuator plate of a monopole type(polarization direction is one in the thickness direction) may be used.

In the above-described embodiment, a configuration in which theplurality of channels 54 and 55 have shapes which are different fromeach other is described. However, it is not limited thereto. That is,the plurality of channels 54 and 55 may have the same shape.

In the above-described embodiment, a configuration in which the lengthof the non-discharge channel 55 in the Z-direction is longer than thelength of the discharge channel 54 in the Z-direction is described.However, it is not limited thereto. For example, the length of thenon-discharge channel 55 in the Z-direction may be equal to or smallerthan the length of the discharge channel 54 in the Z-direction.

In the above-described embodiment, a configuration in which the jointcommon electrode 82 which is connected to the plurality of common leadwirings 67 is formed on the CP-side-Y-direction inner side surface 52 f2 is described. However, it is not limited thereto. For example, thejoint common electrode 82 may not be formed on the CP-side-Y-directioninner side surface 52 f 2. That is, a portion between two common leadwiring 67 which are adjacent to each other may be not electricallyconnected to a portion between another two common lead wirings 67 whichare adjacent to each other, on the CP-side-Y-direction inner sidesurface 52 f 2.

In the above-described embodiment, a configuration in which the flowpassage plate 41 is integrally formed of the same member is described.However, it is not limited to only this configuration. For example, theflow passage plate 41 may be formed by an assembly of a plurality ofmembers.

In the following modification examples, components which are the same asthose in the embodiment are denoted by the same reference signs, anddescriptions thereof will not be repeated.

First Modification Example

For example, as illustrated in FIG. 23, a transverse common electrode 80which is connected to the plurality of CP-side common pads 66 may beformed on the CP-side-Y-direction outer side surface 52 f 1. In thetransverse common electrode 80, a portion of the CP-side-Y-directionouter side surface 52 f 1, which is positioned between the slit 72 andthe CP-side individual pad 69 a extends in the X-direction. Thetransverse common electrode 80 is formed to have a band shape in theX-direction, on the CP-side-Y-direction outer side surface 52 f 1. Thetransverse common electrode 80 is connected to upper end portions of theplurality of CP-side common pads 66, on the CP-side-Y-direction outerside surface 52 f 1. The transverse common electrode 80 does not abut onthe CP-side individual pad 69 a, on the CP-side-Y-direction outer sidesurface 52 f 1.

The through-hole 87 may have a slit shape which is long in the extensiondirection of the transverse common electrode 80. For example, the lengthof the through-hole 87 in a longitudinal direction thereof is set to besubstantially equal to the array pitch between two slits 72 which areadjacent to each other. The length of the through-hole 87 and the numberof through-holes 87 which are disposed may be appropriately changed.

A clearance groove 81 (referred to as “an electrode clearance groove 81”below) of the transverse common electrode 80 may be formed in the innerside surface of the AP-side tail portion 51 e in the Y-direction. In theelectrode clearance groove 81, a portion of the inner side surface ofthe AP-side tail portion 51 e in the Y-direction, which is positionedbetween the AP-side common pad 62 and the AP-side individual wiring 64extends in the X-direction. The electrode clearance groove 81 faces thetransverse common electrode 80 in the Y-direction. The electrodeclearance groove 81 is disposed at a position corresponding to that ofthe transverse common electrode 80 when the actuator plate 51 and thecover plate 52 are bonded to each other. That is, when the actuatorplate 51 and the cover plate 52 are bonded to each other, the transversecommon electrode 80 is disposed in the electrode clearance groove 81.

In this modification example, the transverse common electrode 80 whichis connected to the plurality of CP-side common pads 66 and extends inthe X-direction is formed on the CP-side-Y-direction outer side surface52 f 1.

According to this modification example, it is possible to preliminarilyconnect the plurality of CP-side common pads 66 by the transverse commonelectrode 80. Thus, it is possible to improve reliability for electricalconnection of the plurality of CP-side common pads 66, in comparison toa case where the plurality of CP-side common pads 66 are connected toonly the in-through-hole electrodes 86.

In this modification example, the electrode clearance groove 81 whichextends in the X-direction and faces the transverse common electrode 80in the Y-direction is formed in the inner side surface of the AP-sidetail portion 51 e in the Y-direction.

According to this modification example, when the actuator plate 51 andthe cover plate 52 are bonded to each other, the transverse commonelectrode 80 can be accommodated in the electrode clearance groove 81.Thus, it is possible to avoid an occurrence of short circuit between theelectrode on the actuator plate 51 side (for example, AP-side individualwiring 64), and the transverse common electrode 80.

In this modification example, the through-hole 87 may have a slit shapewhich is long in the extension direction of the transverse commonelectrode 80.

According to this modification example, in comparison to a case wherethe through-hole is formed to be circular, it is easy to increase theregion of forming the in-through-hole electrode 86. Thus, it is possibleto improve reliability of electrical connection between thein-through-hole electrode 86 and the transverse common electrode 80. Inaddition, it is sufficient that the through-hole 87 is extended only inthe extension direction (X-direction) of the transverse common electrode80. Thus, it is possible to reduce the length of each of the head chips40A and 40B in the Z-direction.

Second Modification Example

For example, as illustrated in FIG. 24, instead of the recess portion 73(see FIG. 4) in the embodiment, a plurality of through-holes 90 may beformed at the upper end portion of the cover plate 52. The through-holespenetrate in the Y-direction and are arranged to be spaced from eachother in the X-direction.

The common lead wiring 67 extends upwardly on the CP-side-Y-directioninner side surface 52 f 2 from the through-hole 85 along theCP-side-Y-direction inner side surface 52 f 2. Then, the common leadwiring 67 is drawn up to the upper end portion of theCP-side-Y-direction outer side surface 52 f 1 through the through-hole90 at the upper end portion of the cover plate 52. In other words, thecommon lead wiring 67 is drawn up to the outer side surface of theCP-side tail portion 52 e in the Y-direction, through athrough-electrode 91 in the through-hole 90. Thus, the common electrode61 formed on the inner surface of each of the plurality of dischargechannels 54 is electrically connected to the flexible substrate 45 atthe common terminal 68, through the AP-side common pad 62, the CP-sidecommon pad 66, the in-through-hole electrode 86, and the common leadwiring 67.

For example, the through-electrode 91 is formed only on an innercircumferential surface of the through-hole 90 by vapor deposition orthe like. The through-hole 90 may be full of the through-electrode 91 byusing a conductive paste or the like.

In this modification example, the plurality of through-holes 90 whichpenetrate the cover plate 52 in the Y-direction and are arranged to bespaced from each other in the X-direction are formed at the upper endportion of the CP-side tail portion 52 e. The common lead wiring 67 isconnected to the in-through-hole electrode 86 and the flexible substrate45 through the through-hole 90.

According to this modification example, in comparison to a case wherethe common lead wiring 67 is connected to the in-through-hole electrode86 and the flexible substrate 45 along the recess portion 73 (see FIG.4), it is possible to protect the common lead wiring 67 by athrough-hole forming portion (wall portion). Thus, it is possible toavoid an occurrence of a situation in which the common lead wiring 67 inthe through-hole 90 is damaged.

In addition, in the range without departing from the gist of the presentinvention, the components in the above-described embodiment may beappropriately substituted with known components, or the above-describedmodification examples may be appropriately combined.

What is claimed is:
 1. A liquid ejecting head chip comprising: anactuator plate in which a plurality of channels are arranged at adistance in a second direction which is orthogonal to a first direction,and of which each includes an extension portion and a raise-and-cutportion, the extension portion extending in the first direction, and theraise-and-cut portion continuing from the extension portion toward oneside of the first direction and having a groove depth which is graduallyreduced toward the one side of the first direction; and an in-channelelectrode which is formed on an inner surface of each of the channelswith a plating film; wherein the plurality of channels include ejectionchannels and non-ejection channels which are alternately arranged at adistance in the second direction, and wherein both of the ejectionchannels and non-ejection channels include the raise-and-cut portions.2. The liquid ejecting head chip according to claim 1, wherein theplurality of channels have shapes which are different from each other.3. The liquid ejecting head chip according to claim 2, wherein thein-channel electrode includes a common electrode formed on an innersurface of each of the ejection channels and an individual electrodeformed on an inner surface of each of the non-ejection channels, and alength of the non-ejection channel in the first direction is longer thana length of the ejection channel in the first direction.
 4. The liquidejecting head chip according to claim 3, further comprising: a coverplate which is stacked on an actuator plate-side first main surface ofthe actuator plate in a third direction which is orthogonal to the firstdirection and the second direction, so as to close the ejection channelsand the non-ejection channels in the actuator plate, and in which aliquid supply passage is formed to communicate with the ejection channeland a through-hole is formed to penetrate the cover plate in the thirddirection and disposed at a place in which the liquid supply passage isnot formed; and a connection wiring that connects the common electrodeto an external wiring through the through-hole in the cover plate. 5.The liquid ejecting head chip according to claim 4, wherein theconnection wiring is formed at a tail portion of the cover plate, whichextends out of one end surface of the actuator plate in the firstdirection, in a stacked state of the actuator plate and the cover plate.6. The liquid ejecting head chip according to claim 5, wherein theconnection wiring includes an in-through-hole electrode which is formedon an inner surface of the through-hole, and a lead wiring that connectsthe in-through-hole electrode to the external wiring at the tail portionof the cover plate.
 7. The liquid ejecting head chip according to claim6, wherein the lead wiring includes a common terminal which is dividedso as to be formed in at least three or more places in the seconddirection on a cover plate-side first main surface facing the actuatorplate-side first main surface and is connected to the external wiring,in the tail portion of the cover plate.
 8. The liquid ejecting head chipaccording to claim 6, wherein a plurality of actuator plate-side commonpads which respectively extend from the common electrodes and aredisposed to be spaced from each other in the second direction are formedat a portion of the actuator plate-side first main surface, which ispositioned on one side of the ejection channel in the first direction,and a plurality of cover plate-side common pads which extend fromin-through-hole electrodes, are disposed to be spaced from each other inthe second direction, and face the actuator plate-side common pads inthe third direction are formed around through-holes in a coverplate-side first main surface of the cover plate, which faces theactuator plate-side first main surface, respectively.
 9. The liquidejecting head chip according to claim 8, wherein a transverse commonelectrode which is connected to the plurality of cover plate-side commonpads and extends in the second direction is formed on the coverplate-side first main surface.
 10. The liquid ejecting head chipaccording to claim 4, Wherein, on the actuator plate-side first mainsurface, an actuator plate-side individual wiring which extends in thesecond direction at one end portion thereof in the first direction andconnects individual electrodes which face each other with the ejectionchannel interposed between the individual electrodes is formed, in thecover plate on the cover plate-side first main surface which faces theactuator plate-side first main surface, a cover plate-side individualwiring which is divided in the second direction at the one end portionthereof in the first direction is formed, and the cover plate-sideindividual wiring includes a cover plate-side individual pad which facesthe actuator plate-side individual wiring in the third direction, and anindividual terminal which extends from the cover plate-side individualpad toward one end in the first direction.
 11. A liquid ejecting headcomprising: the liquid ejecting head chip according to claim
 1. 12. Theliquid ejecting head according to claim 11, wherein the plurality ofchannels include ejection channels and non-ejection channels which arealternately arranged at a distance in the second direction, the liquidejecting head chip includes a cover plate which is stacked on anactuator plate-side first main surface of the actuator plate in a thirddirection which is orthogonal to the first direction and the seconddirection, so as to close the ejection channels and the non-ejectionchannels in the actuator plate, and in which a liquid supply passagewhich communicates with the ejection channel is formed, a pair of liquidejecting head chips which is disposed such that cover plate-side secondmain surfaces which are opposite to cover plate-side first main surfacesrespectively facing the actuator plate-side first main surfaces in thecover plate face each other in the third direction, a flow passage plateis disposed between the pair of liquid ejecting head chips, and an inletflow passage which communicates with the liquid supply passages of thepair of the cover plates is formed in the flow passage plate.
 13. Theliquid ejecting head according to claim 12, wherein each of theplurality of ejection channels is opened in the other end surface of theactuator plate in the first direction in each of the pair of liquidejecting head chips, an ejection plate which has ejection holes whichrespectively communicate with the ejection channels is disposed on theother end side of each of the pair of actuator plates in the firstdirection, a return plate which has circulation passages which cause theejection channels to respectively communicate with the ejection holes isdisposed between the pair of actuator plates and the ejection plate inthe first direction, and an outlet flow passage which communicates withthe circulation passages is formed in the flow passage plate.
 14. Aliquid ejecting apparatus comprising: the liquid ejecting head accordingto claim 11; and a moving mechanism that relatively moves the liquidejecting head and a recording medium.